refactor(app): reshape session store reads around narrow hook surface

Eliminate sidebar re-render cascades by fixing both sides of the subscription contract: - Session-store writes preserve identity: setWorkspaces, mergeWorkspaces, removeWorkspace, and patchWorkspaceScripts return the previous Map/entry reference when content is unchanged. - HostRuntimeController.updateSnapshot only notifies when a patched field actually changed; idle probe ticks no longer replace the snapshot. - New canonical hook surface in stores/session-store-hooks.ts (useWorkspace, useWorkspaceFields, useWorkspaceStructure, useWorkspaceKeys, useResolveWorkspaceIdByCwd, useWorkspaceStatusesForBadges, useWorkspaceExecutionAuthority, useRecommendedProjectPaths, useHasWorkspaces). These are the only place to subscribe to workspaces. - 15 greedy subscribers migrated to the hook surface. The sidebar is now driven by useWorkspaceStructure for identity/ordering; each row hydrates its own descriptor via useWorkspaceFields, so a workspace update re-renders only its row. Archive-redirect callbacks switched to event-time useSessionStore.getState(). - Deleted dead code: use-session-directory.ts, workspace-fetch-debug.ts, and the unused SidebarProjectEntry aggregates (activeCount, totalWorkspaces, aggregated statusBucket). No user-visible behavior change. Targeted tests green (79 tests across host-runtime, session-store, session-store-hooks, sidebar list, sidebar row model, sidebar shortcuts, workspace source of truth).
2026-07-29 12:01:31 +00:00 · 2026-04-19 20:19:45 +07:00
parent 8991d34f78
commit bd1fb311ea
27 changed files with 1797 additions and 623 deletions
--- a/package-lock.json
+++ b/package-lock.json
@@ -12765,6 +12765,93 @@
        "url": "https://github.com/sponsors/tannerlinsley"
      }
    },
+    "node_modules/@testing-library/dom": {
+      "version": "10.4.1",
+      "resolved": "https://registry.npmjs.org/@testing-library/dom/-/dom-10.4.1.tgz",
+      "integrity": "sha512-o4PXJQidqJl82ckFaXUeoAW+XysPLauYI43Abki5hABd853iMhitooc6znOnczgbTYmEP6U6/y1ZyKAIsvMKGg==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "@babel/code-frame": "^7.10.4",
+        "@babel/runtime": "^7.12.5",
+        "@types/aria-query": "^5.0.1",
+        "aria-query": "5.3.0",
+        "dom-accessibility-api": "^0.5.9",
+        "lz-string": "^1.5.0",
+        "picocolors": "1.1.1",
+        "pretty-format": "^27.0.2"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    },
+    "node_modules/@testing-library/dom/node_modules/ansi-styles": {
+      "version": "5.2.0",
+      "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-5.2.0.tgz",
+      "integrity": "sha512-Cxwpt2SfTzTtXcfOlzGEee8O+c+MmUgGrNiBcXnuWxuFJHe6a5Hz7qwhwe5OgaSYI0IJvkLqWX1ASG+cJOkEiA==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true,
+      "engines": {
+        "node": ">=10"
+      },
+      "funding": {
+        "url": "https://github.com/chalk/ansi-styles?sponsor=1"
+      }
+    },
+    "node_modules/@testing-library/dom/node_modules/pretty-format": {
+      "version": "27.5.1",
+      "resolved": "https://registry.npmjs.org/pretty-format/-/pretty-format-27.5.1.tgz",
+      "integrity": "sha512-Qb1gy5OrP5+zDf2Bvnzdl3jsTf1qXVMazbvCoKhtKqVs4/YK4ozX4gKQJJVyNe+cajNPn0KoC0MC3FUmaHWEmQ==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "ansi-regex": "^5.0.1",
+        "ansi-styles": "^5.0.0",
+        "react-is": "^17.0.1"
+      },
+      "engines": {
+        "node": "^10.13.0 || ^12.13.0 || ^14.15.0 || >=15.0.0"
+      }
+    },
+    "node_modules/@testing-library/dom/node_modules/react-is": {
+      "version": "17.0.2",
+      "resolved": "https://registry.npmjs.org/react-is/-/react-is-17.0.2.tgz",
+      "integrity": "sha512-w2GsyukL62IJnlaff/nRegPQR94C/XXamvMWmSHRJ4y7Ts/4ocGRmTHvOs8PSE6pB3dWOrD/nueuU5sduBsQ4w==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true
+    },
+    "node_modules/@testing-library/react": {
+      "version": "16.3.2",
+      "resolved": "https://registry.npmjs.org/@testing-library/react/-/react-16.3.2.tgz",
+      "integrity": "sha512-XU5/SytQM+ykqMnAnvB2umaJNIOsLF3PVv//1Ew4CTcpz0/BRyy/af40qqrt7SjKpDdT1saBMc42CUok5gaw+g==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@babel/runtime": "^7.12.5"
+      },
+      "engines": {
+        "node": ">=18"
+      },
+      "peerDependencies": {
+        "@testing-library/dom": "^10.0.0",
+        "@types/react": "^18.0.0 || ^19.0.0",
+        "@types/react-dom": "^18.0.0 || ^19.0.0",
+        "react": "^18.0.0 || ^19.0.0",
+        "react-dom": "^18.0.0 || ^19.0.0"
+      },
+      "peerDependenciesMeta": {
+        "@types/react": {
+          "optional": true
+        },
+        "@types/react-dom": {
+          "optional": true
+        }
+      }
+    },
    "node_modules/@testing-library/react-hooks": {
      "version": "7.0.2",
      "resolved": "https://registry.npmjs.org/@testing-library/react-hooks/-/react-hooks-7.0.2.tgz",
@@ -12880,6 +12967,14 @@
        "tslib": "^2.4.0"
      }
    },
+    "node_modules/@types/aria-query": {
+      "version": "5.0.4",
+      "resolved": "https://registry.npmjs.org/@types/aria-query/-/aria-query-5.0.4.tgz",
+      "integrity": "sha512-rfT93uj5s0PRL7EzccGMs3brplhcrghnDoV26NqKhCAS1hVo+WdNsPvE/yb6ilfr5hi2MEk6d5EWJTKdxg8jVw==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true
+    },
    "node_modules/@types/babel__core": {
      "version": "7.20.5",
      "resolved": "https://registry.npmjs.org/@types/babel__core/-/babel__core-7.20.5.tgz",
@@ -14893,6 +14988,17 @@
        "node": ">=10"
      }
    },
+    "node_modules/aria-query": {
+      "version": "5.3.0",
+      "resolved": "https://registry.npmjs.org/aria-query/-/aria-query-5.3.0.tgz",
+      "integrity": "sha512-b0P0sZPKtyu8HkeRAfCq0IfURZK+SuwMjY1UXGBU27wpAiTwQAIlq56IbIO+ytk/JjS1fMR14ee5WBBfKi5J6A==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "peer": true,
+      "dependencies": {
+        "dequal": "^2.0.3"
+      }
+    },
    "node_modules/array-buffer-byte-length": {
      "version": "1.0.2",
      "resolved": "https://registry.npmjs.org/array-buffer-byte-length/-/array-buffer-byte-length-1.0.2.tgz",
@@ -18008,6 +18114,14 @@
        "node": ">=0.10.0"
      }
    },
+    "node_modules/dom-accessibility-api": {
+      "version": "0.5.16",
+      "resolved": "https://registry.npmjs.org/dom-accessibility-api/-/dom-accessibility-api-0.5.16.tgz",
+      "integrity": "sha512-X7BJ2yElsnOJ30pZF4uIIDfBEVgF4XEBxL9Bxhy6dnrm5hkzqmsWHGTiHqRiITNhMyFLyAiWndIJP7Z1NTteDg==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true
+    },
    "node_modules/dom-serializer": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/dom-serializer/-/dom-serializer-2.0.0.tgz",
@@ -27199,6 +27313,17 @@
        "react-native-svg": "^12.0.0 || ^13.0.0 || ^14.0.0 || ^15.0.0"
      }
    },
+    "node_modules/lz-string": {
+      "version": "1.5.0",
+      "resolved": "https://registry.npmjs.org/lz-string/-/lz-string-1.5.0.tgz",
+      "integrity": "sha512-h5bgJWpxJNswbU7qCrV0tIKQCaS3blPDrqKWx+QxzuzL1zGUzij9XCWLrSLsJPu5t+eWA/ycetzYAO5IOMcWAQ==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true,
+      "bin": {
+        "lz-string": "bin/bin.js"
+      }
+    },
    "node_modules/magic-string": {
      "version": "0.30.21",
      "resolved": "https://registry.npmjs.org/magic-string/-/magic-string-0.30.21.tgz",
@@ -37233,6 +37358,7 @@
        "expo-system-ui": "~6.0.7",
        "expo-updates": "~29.0.12",
        "expo-web-browser": "~15.0.8",
+        "fast-deep-equal": "^3.1.3",
        "lucide-react-native": "^0.546.0",
        "mnemonic-id": "^3.2.7",
        "react": "19.1.0",
@@ -37261,6 +37387,7 @@
      },
      "devDependencies": {
        "@playwright/test": "^1.56.1",
+        "@testing-library/react": "^16.3.2",
        "@types/react": "~19.2.0",
        "@types/ws": "^8.18.1",
        "eas-cli": "^16.24.1",
--- a/packages/app/package.json
+++ b/packages/app/package.json
@@ -79,6 +79,7 @@
    "expo-system-ui": "~6.0.7",
    "expo-updates": "~29.0.12",
    "expo-web-browser": "~15.0.8",
+    "fast-deep-equal": "^3.1.3",
    "lucide-react-native": "^0.546.0",
    "mnemonic-id": "^3.2.7",
    "react": "19.1.0",
@@ -107,6 +108,7 @@
  },
  "devDependencies": {
    "@playwright/test": "^1.56.1",
+    "@testing-library/react": "^16.3.2",
    "@types/react": "~19.2.0",
    "@types/ws": "^8.18.1",
    "eas-cli": "^16.24.1",
--- a/packages/app/src/app/h/[serverId]/agent/[agentId].tsx
+++ b/packages/app/src/app/h/[serverId]/agent/[agentId].tsx
@@ -2,6 +2,7 @@ import { useEffect, useRef } from "react";
 import { useLocalSearchParams, useRouter } from "expo-router";
 import { HostRouteBootstrapBoundary } from "@/components/host-route-bootstrap-boundary";
 import { useSessionStore } from "@/stores/session-store";
+import { useResolveWorkspaceIdByCwd } from "@/stores/session-store-hooks";
 import { useHostRuntimeClient, useHostRuntimeIsConnected } from "@/runtime/host-runtime";
 import { buildHostRootRoute } from "@/utils/host-routes";
 import { resolveWorkspaceIdByExecutionDirectory } from "@/utils/workspace-execution";
@@ -32,21 +33,10 @@ function HostAgentReadyRouteContent() {
    }
    return state.sessions[serverId]?.agents?.get(agentId)?.cwd ?? null;
  });
-  const sessionWorkspaces = useSessionStore((state) =>
-    serverId ? state.sessions[serverId]?.workspaces : undefined,
-  );
  const hasHydratedWorkspaces = useSessionStore((state) =>
    serverId ? (state.sessions[serverId]?.hasHydratedWorkspaces ?? false) : false,
  );
-  const resolvedWorkspaceId = useSessionStore((state) => {
-    if (!serverId || !agentId) {
-      return null;
-    }
-    return resolveWorkspaceIdByExecutionDirectory({
-      workspaces: state.sessions[serverId]?.workspaces?.values(),
-      workspaceDirectory: state.sessions[serverId]?.agents?.get(agentId)?.cwd,
-    });
-  });
+  const resolvedWorkspaceId = useResolveWorkspaceIdByCwd(serverId, agentCwd);

  useEffect(() => {
    if (redirectedRef.current) {
@@ -102,8 +92,9 @@ function HostAgentReadyRouteContent() {
          return;
        }
        const cwd = result?.agent?.cwd?.trim();
+        const workspaces = useSessionStore.getState().sessions[serverId]?.workspaces;
        const workspaceId = resolveWorkspaceIdByExecutionDirectory({
-          workspaces: sessionWorkspaces?.values(),
+          workspaces: workspaces?.values(),
          workspaceDirectory: cwd,
        });
        if (!workspaceId && !hasHydratedWorkspaces) {
@@ -133,7 +124,7 @@ function HostAgentReadyRouteContent() {
    return () => {
      cancelled = true;
    };
-  }, [agentId, client, hasHydratedWorkspaces, isConnected, router, serverId, sessionWorkspaces]);
+  }, [agentId, client, hasHydratedWorkspaces, isConnected, router, serverId]);

  return null;
 }
--- a/packages/app/src/components/project-picker-modal.tsx
+++ b/packages/app/src/components/project-picker-modal.tsx
@@ -6,7 +6,7 @@ import { useQuery } from "@tanstack/react-query";
 import { usePathname } from "expo-router";
 import { useKeyboardShortcutsStore } from "@/stores/keyboard-shortcuts-store";
 import { shortenPath } from "@/utils/shorten-path";
-import { useSessionStore } from "@/stores/session-store";
+import { useRecommendedProjectPaths } from "@/stores/session-store-hooks";
 import { useHosts, useHostRuntimeClient, useHostRuntimeIsConnected } from "@/runtime/host-runtime";
 import { useOpenProject } from "@/hooks/use-open-project";
 import { parseServerIdFromPathname } from "@/utils/host-routes";
@@ -29,9 +29,7 @@ export function ProjectPickerModal() {

  const client = useHostRuntimeClient(serverId ?? "");
  const isConnected = useHostRuntimeIsConnected(serverId ?? "");
-  const workspaces = useSessionStore((state) =>
-    serverId ? state.sessions[serverId]?.workspaces : undefined,
-  );
+  const recommendedPaths = useRecommendedProjectPaths(serverId);

  const inputRef = useRef<TextInput>(null);
  const [query, setQuery] = useState("");
@@ -39,13 +37,6 @@ export function ProjectPickerModal() {
  const [isSubmitting, setIsSubmitting] = useState(false);
  const openProject = useOpenProject(serverId);

-  const recommendedPaths = useMemo(() => {
-    if (!workspaces) return [];
-    return Array.from(workspaces.values())
-      .map((workspace) => workspace.projectRootPath)
-      .filter((path) => path.length > 0);
-  }, [workspaces]);
-
  const directorySuggestionsQuery = useQuery({
    queryKey: ["project-picker-directory-suggestions", serverId, query],
    queryFn: async () => {
--- a/packages/app/src/components/sidebar-workspace-list.test.tsx
+++ b/packages/app/src/components/sidebar-workspace-list.test.tsx
@@ -0,0 +1,337 @@
+/**
+ * @vitest-environment jsdom
+ */
+import { act } from "@testing-library/react";
+import type { DaemonClient } from "@server/client/daemon-client";
+import type { WorkspaceScriptPayload } from "@server/shared/messages";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { createRoot, type Root } from "react-dom/client";
+import React from "react";
+import type { ReactElement } from "react";
+
+vi.hoisted(() => {
+  (globalThis as unknown as { __DEV__: boolean }).__DEV__ = false;
+});
+
+import {
+  createSidebarWorkspaceEntry,
+  type SidebarProjectEntry,
+} from "@/hooks/use-sidebar-workspaces-list";
+import { useSidebarWorkspacesList } from "@/hooks/use-sidebar-workspaces-list";
+import { patchWorkspaceScripts } from "@/contexts/session-workspace-scripts";
+import {
+  getHostRuntimeStore,
+  type HostRuntimeController,
+  type HostRuntimeSnapshot,
+} from "@/runtime/host-runtime";
+import type { HostProfile } from "@/types/host-connection";
+import { useSessionStore, type WorkspaceDescriptor } from "@/stores/session-store";
+import { useSidebarOrderStore } from "@/stores/sidebar-order-store";
+import { useWorkspaceFields } from "@/stores/session-store-hooks";
+
+vi.mock("@react-native-async-storage/async-storage", () => ({
+  default: {
+    getItem: vi.fn(),
+    setItem: vi.fn(),
+    removeItem: vi.fn(),
+  },
+}));
+
+const SERVER_ID = "sidebar-render-count";
+
+type RenderCounts = {
+  frame: number;
+  headers: Record<string, number>;
+  rows: Record<string, number>;
+};
+
+const runningScript: WorkspaceScriptPayload = {
+  scriptName: "web",
+  type: "service",
+  hostname: "web.paseo.localhost",
+  port: 3000,
+  proxyUrl: "http://web.paseo.localhost:6767",
+  lifecycle: "running",
+  health: "healthy",
+  exitCode: null,
+};
+
+function workspace(input: {
+  id: string;
+  projectId: string;
+  projectDisplayName: string;
+  name: string;
+  status?: WorkspaceDescriptor["status"];
+  scripts?: WorkspaceDescriptor["scripts"];
+}): WorkspaceDescriptor {
+  return {
+    id: input.id,
+    projectId: input.projectId,
+    projectDisplayName: input.projectDisplayName,
+    projectRootPath: `/repo/${input.projectId}`,
+    workspaceDirectory: `/repo/${input.projectId}/${input.id}`,
+    projectKind: "git",
+    workspaceKind: input.name === "main" ? "local_checkout" : "worktree",
+    name: input.name,
+    status: input.status ?? "done",
+    diffStat: null,
+    scripts: input.scripts ?? [],
+  };
+}
+
+function createWorkspaces(): WorkspaceDescriptor[] {
+  return [
+    workspace({
+      id: "a-main",
+      projectId: "project-a",
+      projectDisplayName: "Project A",
+      name: "main",
+      scripts: [runningScript],
+    }),
+    workspace({
+      id: "a-one",
+      projectId: "project-a",
+      projectDisplayName: "Project A",
+      name: "one",
+    }),
+    workspace({
+      id: "a-two",
+      projectId: "project-a",
+      projectDisplayName: "Project A",
+      name: "two",
+    }),
+    workspace({
+      id: "b-main",
+      projectId: "project-b",
+      projectDisplayName: "Project B",
+      name: "main",
+    }),
+    workspace({
+      id: "b-one",
+      projectId: "project-b",
+      projectDisplayName: "Project B",
+      name: "one",
+    }),
+    workspace({
+      id: "b-two",
+      projectId: "project-b",
+      projectDisplayName: "Project B",
+      name: "two",
+    }),
+  ];
+}
+
+function makeHost(): HostProfile {
+  const now = "2026-04-19T00:00:00.000Z";
+  return {
+    serverId: SERVER_ID,
+    label: "Render Count Host",
+    lifecycle: {},
+    connections: [],
+    preferredConnectionId: null,
+    createdAt: now,
+    updatedAt: now,
+  };
+}
+
+function initializeSidebarState(workspaces: WorkspaceDescriptor[]): void {
+  act(() => {
+    getHostRuntimeStore().syncHosts([makeHost()]);
+    useSessionStore.getState().initializeSession(SERVER_ID, null as unknown as DaemonClient);
+    useSessionStore
+      .getState()
+      .setWorkspaces(SERVER_ID, new Map(workspaces.map((entry) => [entry.id, entry])));
+    useSessionStore.getState().setHasHydratedWorkspaces(SERVER_ID, true);
+    useSidebarOrderStore.setState({
+      projectOrderByServerId: {
+        [SERVER_ID]: ["project-a", "project-b"],
+      },
+      workspaceOrderByServerAndProject: {
+        [`${SERVER_ID}::project-a`]: [
+          `${SERVER_ID}:a-main`,
+          `${SERVER_ID}:a-one`,
+          `${SERVER_ID}:a-two`,
+        ],
+        [`${SERVER_ID}::project-b`]: [
+          `${SERVER_ID}:b-main`,
+          `${SERVER_ID}:b-one`,
+          `${SERVER_ID}:b-two`,
+        ],
+      },
+    });
+  });
+}
+
+function resetCounts(counts: RenderCounts): void {
+  counts.frame = 0;
+  counts.headers = {};
+  counts.rows = {};
+}
+
+function incrementRecord(record: Record<string, number>, key: string): void {
+  record[key] = (record[key] ?? 0) + 1;
+}
+
+function ProjectHeaderProbe({
+  project,
+  counts,
+}: {
+  project: SidebarProjectEntry;
+  counts: RenderCounts;
+}): null {
+  incrementRecord(counts.headers, project.projectKey);
+  return null;
+}
+
+function WorkspaceRowProbe({
+  serverId,
+  workspaceId,
+  counts,
+}: {
+  serverId: string;
+  workspaceId: string;
+  counts: RenderCounts;
+}): null {
+  const workspace = useWorkspaceFields(serverId, workspaceId, (entry) =>
+    createSidebarWorkspaceEntry({ serverId, workspace: entry }),
+  );
+  if (workspace) {
+    incrementRecord(counts.rows, workspace.workspaceId);
+  }
+  return null;
+}
+
+function SidebarFrameProbe({ counts }: { counts: RenderCounts }): ReactElement {
+  counts.frame += 1;
+  const { projects } = useSidebarWorkspacesList({ serverId: SERVER_ID });
+
+  return (
+    <>
+      {projects.map((project) => (
+        <div key={project.projectKey}>
+          <ProjectHeaderProbe project={project} counts={counts} />
+          {project.workspaces.map((workspace) => (
+            <WorkspaceRowProbe
+              key={workspace.workspaceKey}
+              serverId={workspace.serverId}
+              workspaceId={workspace.workspaceId}
+              counts={counts}
+            />
+          ))}
+        </div>
+      ))}
+    </>
+  );
+}
+
+function getHostController(): HostRuntimeController {
+  const controllers = (
+    getHostRuntimeStore() as unknown as {
+      controllers: Map<string, HostRuntimeController>;
+    }
+  ).controllers;
+  const controller = controllers.get(SERVER_ID);
+  if (!controller) {
+    throw new Error("Host runtime controller was not initialized");
+  }
+  return controller;
+}
+
+function updateControllerSnapshot(
+  patch: Partial<Omit<HostRuntimeSnapshot, "serverId" | "clientGeneration">>,
+): void {
+  (
+    getHostController() as unknown as {
+      updateSnapshot: (
+        patch: Partial<Omit<HostRuntimeSnapshot, "serverId" | "clientGeneration">>,
+      ) => void;
+    }
+  ).updateSnapshot(patch);
+}
+
+async function renderProbe(counts: RenderCounts): Promise<{ root: Root; container: HTMLElement }> {
+  const container = document.createElement("div");
+  document.body.appendChild(container);
+  const root = createRoot(container);
+  await act(async () => {
+    root.render(<SidebarFrameProbe counts={counts} />);
+  });
+  resetCounts(counts);
+  return { root, container };
+}
+
+describe("sidebar workspace render isolation", () => {
+  let root: Root | null = null;
+  let container: HTMLElement | null = null;
+
+  beforeEach(async () => {
+    initializeSidebarState(createWorkspaces());
+  });
+
+  afterEach(() => {
+    if (root) {
+      act(() => {
+        root?.unmount();
+      });
+    }
+    root = null;
+    container?.remove();
+    container = null;
+    act(() => {
+      getHostRuntimeStore().syncHosts([]);
+      useSessionStore.getState().clearSession(SERVER_ID);
+      useSidebarOrderStore.setState({
+        projectOrderByServerId: {},
+        workspaceOrderByServerAndProject: {},
+      });
+    });
+  });
+
+  it("re-renders only the changed workspace row for a status update", async () => {
+    const counts: RenderCounts = { frame: 0, headers: {}, rows: {} };
+    ({ root, container } = await renderProbe(counts));
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [
+        {
+          ...createWorkspaces()[1]!,
+          status: "running",
+        },
+      ]);
+    });
+
+    expect(counts.frame).toBe(0);
+    expect(counts.headers).toEqual({});
+    expect(counts.rows).toEqual({ "a-one": 1 });
+  });
+
+  it("does not re-render the sidebar for a host-runtime probe tick with no content change", async () => {
+    const counts: RenderCounts = { frame: 0, headers: {}, rows: {} };
+    ({ root, container } = await renderProbe(counts));
+
+    act(() => {
+      const probeByConnectionId = getHostController().getSnapshot().probeByConnectionId;
+      updateControllerSnapshot({
+        probeByConnectionId: new Map(probeByConnectionId),
+      });
+    });
+
+    expect(counts).toEqual({ frame: 0, headers: {}, rows: {} });
+  });
+
+  it("does not re-render for a deep-equal scripts patch", async () => {
+    const counts: RenderCounts = { frame: 0, headers: {}, rows: {} };
+    ({ root, container } = await renderProbe(counts));
+
+    act(() => {
+      useSessionStore.getState().setWorkspaces(SERVER_ID, (current) =>
+        patchWorkspaceScripts(current, {
+          workspaceId: "a-main",
+          scripts: [{ ...runningScript }],
+        }),
+      );
+    });
+
+    expect(counts).toEqual({ frame: 0, headers: {}, rows: {} });
+  });
+});
--- a/packages/app/src/components/sidebar-workspace-list.tsx
+++ b/packages/app/src/components/sidebar-workspace-list.tsx
@@ -56,6 +56,7 @@ import {
 } from "@/utils/host-routes";
 import { prepareWorkspaceTab } from "@/utils/workspace-navigation";
 import {
+  createSidebarWorkspaceEntry,
  type SidebarProjectEntry,
  type SidebarWorkspaceEntry,
 } from "@/hooks/use-sidebar-workspaces-list";
@@ -92,7 +93,12 @@ import { useKeyboardActionHandler } from "@/hooks/use-keyboard-action-handler";
 import { type PrHint, useWorkspacePrHint } from "@/hooks/use-checkout-pr-status-query";
 import { buildSidebarProjectRowModel } from "@/utils/sidebar-project-row-model";
 import { useNavigationActiveWorkspaceSelection } from "@/stores/navigation-active-workspace-store";
-import { normalizeWorkspaceDescriptor, useSessionStore } from "@/stores/session-store";
+import {
+  normalizeWorkspaceDescriptor,
+  useSessionStore,
+  type WorkspaceDescriptor,
+} from "@/stores/session-store";
+import { useWorkspaceFields } from "@/stores/session-store-hooks";
 import { buildWorkspaceArchiveRedirectRoute } from "@/utils/workspace-archive-navigation";
 import { openExternalUrl } from "@/utils/open-external-url";
 import {
@@ -114,7 +120,6 @@ function toProjectIconDataUri(icon: { mimeType: string; data: string } | null):
 const workspaceKeyExtractor = (workspace: SidebarWorkspaceEntry) => workspace.workspaceKey;

 const projectKeyExtractor = (project: SidebarProjectEntry) => project.projectKey;
-const EMPTY_WORKSPACES = new Map();
 const WORKSPACE_STATUS_DOT_WIDTH = 14;
 const DEFAULT_STATUS_DOT_SIZE = 7;
 const EMPHASIZED_STATUS_DOT_SIZE = 9;
@@ -194,6 +199,19 @@ interface WorkspaceRowInnerProps {
  archiveShortcutKeys?: ShortcutKey[][] | null;
 }

+function useSidebarWorkspaceEntry(
+  serverId: string | null,
+  workspaceId: string | null,
+): SidebarWorkspaceEntry | null {
+  const projectWorkspaceEntry = useCallback(
+    (workspace: WorkspaceDescriptor): SidebarWorkspaceEntry =>
+      createSidebarWorkspaceEntry({ serverId: serverId ?? "", workspace }),
+    [serverId],
+  );
+
+  return useWorkspaceFields(serverId, workspaceId, projectWorkspaceEntry);
+}
+
 export function PrBadge({ hint }: { hint: PrHint }) {
  const { theme } = useUnistyles();
  const [isHovered, setIsHovered] = useState(false);
@@ -1151,9 +1169,6 @@ function WorkspaceRowWithMenu({
  const toast = useToast();
  const activeWorkspaceSelection = useNavigationActiveWorkspaceSelection();
  const archiveWorktree = useCheckoutGitActionsStore((state) => state.archiveWorktree);
-  const sessionWorkspaces = useSessionStore(
-    (state) => state.sessions[workspace.serverId]?.workspaces ?? EMPTY_WORKSPACES,
-  );
  const [isArchivingWorkspace, setIsArchivingWorkspace] = useState(false);
  const workspaceDirectory = resolveWorkspaceExecutionDirectory({
    workspaceDirectory: workspace.workspaceDirectory,
@@ -1181,10 +1196,11 @@ function WorkspaceRowWithMenu({
      buildWorkspaceArchiveRedirectRoute({
        serverId: workspace.serverId,
        archivedWorkspaceId: workspace.workspaceId,
-        workspaces: sessionWorkspaces.values(),
+        workspaces:
+          useSessionStore.getState().sessions[workspace.serverId]?.workspaces.values() ?? [],
      }),
    );
-  }, [activeWorkspaceSelection, sessionWorkspaces, workspace.serverId, workspace.workspaceId]);
+  }, [activeWorkspaceSelection, workspace.serverId, workspace.workspaceId]);

  const handleArchiveWorktree = useCallback(() => {
    if (isArchiving) {
@@ -1378,9 +1394,6 @@ function NonGitProjectRowWithMenuContent({
  const toast = useToast();
  const contextMenu = useContextMenu();
  const activeWorkspaceSelection = useNavigationActiveWorkspaceSelection();
-  const sessionWorkspaces = useSessionStore(
-    (state) => state.sessions[workspace.serverId]?.workspaces ?? EMPTY_WORKSPACES,
-  );
  const [isArchivingWorkspace, setIsArchivingWorkspace] = useState(false);
  const redirectAfterArchive = useCallback(() => {
    if (
@@ -1394,10 +1407,11 @@ function NonGitProjectRowWithMenuContent({
      buildWorkspaceArchiveRedirectRoute({
        serverId: workspace.serverId,
        archivedWorkspaceId: workspace.workspaceId,
-        workspaces: sessionWorkspaces.values(),
+        workspaces:
+          useSessionStore.getState().sessions[workspace.serverId]?.workspaces.values() ?? [],
      }) as any,
    );
-  }, [activeWorkspaceSelection, sessionWorkspaces, workspace.serverId, workspace.workspaceId]);
+  }, [activeWorkspaceSelection, workspace.serverId, workspace.workspaceId]);

  const handleArchiveWorkspace = useCallback(() => {
    if (isArchivingWorkspace) {
@@ -1542,13 +1556,19 @@ function FlattenedProjectRow({
  onRemoveProject?: () => void;
  removeProjectStatus?: "idle" | "pending";
 }) {
+  const workspace = useSidebarWorkspaceEntry(serverId, rowModel.workspace.workspaceId);
+
+  if (!workspace) {
+    return null;
+  }
+
  if (project.projectKind === "directory") {
    return (
      <NonGitProjectRowWithMenu
        project={project}
        displayName={displayName}
        iconDataUri={iconDataUri}
-        workspace={rowModel.workspace}
+        workspace={workspace}
        selected={rowModel.selected}
        onPress={onPress}
        shortcutNumber={shortcutNumber}
@@ -1565,7 +1585,7 @@ function FlattenedProjectRow({
      project={project}
      displayName={displayName}
      iconDataUri={iconDataUri}
-      workspace={rowModel.workspace}
+      workspace={workspace}
      selected={rowModel.selected}
      chevron={rowModel.chevron}
      onPress={onPress}
@@ -1609,9 +1629,15 @@ function WorkspaceRow({
  canCopyBranchName: boolean;
  isCreating?: boolean;
 }) {
+  const hydratedWorkspace = useSidebarWorkspaceEntry(workspace.serverId, workspace.workspaceId);
+
+  if (!hydratedWorkspace) {
+    return null;
+  }
+
  return (
    <WorkspaceRowWithMenu
-      workspace={workspace}
+      workspace={hydratedWorkspace}
      selected={selected}
      shortcutNumber={shortcutNumber}
      showShortcutBadge={showShortcutBadge}
--- a/packages/app/src/contexts/session-workspace-scripts.ts
+++ b/packages/app/src/contexts/session-workspace-scripts.ts
@@ -1,3 +1,4 @@
+import equal from "fast-deep-equal";
 import type { ScriptStatusUpdateMessage } from "@server/shared/messages";
 import type { WorkspaceDescriptor } from "@/stores/session-store";
 import { resolveWorkspaceMapKeyByIdentity } from "@/utils/workspace-execution";
@@ -19,6 +20,10 @@ export function patchWorkspaceScripts(
    return workspaces;
  }

+  if (equal(existing.scripts, update.scripts)) {
+    return workspaces;
+  }
+
  const next = new Map(workspaces);
  next.set(workspaceKey, {
    ...existing,
--- a/packages/app/src/hooks/use-favicon-status.ts
+++ b/packages/app/src/hooks/use-favicon-status.ts
@@ -1,13 +1,9 @@
 import { useEffect, useRef, useState } from "react";
-import { useShallow } from "zustand/shallow";
 import { getIsElectronRuntimeMac } from "@/constants/layout";
 import { useAggregatedAgents } from "./use-aggregated-agents";
 import { getDesktopHost } from "@/desktop/host";
-import { useSessionStore } from "@/stores/session-store";
-import {
-  deriveMacDockBadgeCountFromWorkspaceStatuses,
-  type DesktopBadgeWorkspaceStatus,
-} from "@/utils/desktop-badge-state";
+import { useWorkspaceStatusesForBadges } from "@/stores/session-store-hooks";
+import { deriveMacDockBadgeCountFromWorkspaceStatuses } from "@/utils/desktop-badge-state";
 import { isNative } from "@/constants/platform";

 type FaviconStatus = "none" | "running" | "attention";
@@ -99,17 +95,7 @@ async function updateMacDockBadge(count?: number) {

 export function useFaviconStatus() {
  const { agents } = useAggregatedAgents();
-  const workspaceStatuses = useSessionStore(
-    useShallow((state) => {
-      const statuses: DesktopBadgeWorkspaceStatus[] = [];
-      for (const session of Object.values(state.sessions)) {
-        for (const workspace of session.workspaces.values()) {
-          statuses.push(workspace.status);
-        }
-      }
-      return statuses;
-    }),
-  );
+  const workspaceStatuses = useWorkspaceStatusesForBadges();
  const [colorScheme, setColorScheme] = useState<ColorScheme>(getSystemColorScheme);
  const lastDockBadgeCountRef = useRef<number | undefined>(undefined);

--- a/packages/app/src/hooks/use-providers-snapshot.ts
+++ b/packages/app/src/hooks/use-providers-snapshot.ts
@@ -3,7 +3,7 @@ import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import type { AgentProvider, ProviderSnapshotEntry } from "@server/server/agent/agent-sdk-types";
 import type { DaemonClient } from "@server/client/daemon-client";
 import { useHostRuntimeClient, useHostRuntimeIsConnected } from "@/runtime/host-runtime";
-import { useSessionForServer } from "./use-session-directory";
+import { useSessionStore } from "@/stores/session-store";
 import { queryClient as singletonQueryClient } from "@/query/query-client";

 function normalizeProvidersSnapshotCwdKey(cwd?: string | null): string | null {
@@ -39,9 +39,8 @@ export function useProvidersSnapshot(
  const isConnected = useHostRuntimeIsConnected(serverId ?? "");
  const normalizedCwd = cwd?.trim() || undefined;
  const normalizedCwdKey = normalizeProvidersSnapshotCwdKey(normalizedCwd);
-  const supportsSnapshot = useSessionForServer(
-    serverId,
-    (session) => session?.serverInfo?.features?.providersSnapshot === true,
+  const supportsSnapshot = useSessionStore(
+    (state) => state.sessions[serverId ?? ""]?.serverInfo?.features?.providersSnapshot === true,
  );

  const queryKey = useMemo(
--- a/packages/app/src/hooks/use-session-directory.ts
+++ b/packages/app/src/hooks/use-session-directory.ts
@@ -1,40 +0,0 @@
-import { useCallback, useMemo } from "react";
-import { useStoreWithEqualityFn } from "zustand/traditional";
-import { useSessionStore, type SessionState } from "@/stores/session-store";
-
-export function useSessionDirectory(): Map<string, SessionState> {
-  const sessions = useSessionStore((state) => state.sessions);
-
-  return useMemo(() => {
-    return new Map<string, SessionState>(Object.entries(sessions));
-  }, [sessions]);
-}
-
-type SessionSelector<T> = (session: SessionState | null) => T;
-type EqualityFn<T> = ((left: T, right: T) => boolean) | undefined;
-
-export function useSessionForServer(serverId: string | null): SessionState | null;
-export function useSessionForServer<T>(
-  serverId: string | null,
-  selector: SessionSelector<T>,
-  equalityFn?: EqualityFn<T>,
-): T;
-export function useSessionForServer<T>(
-  serverId: string | null,
-  selector?: SessionSelector<T>,
-  equalityFn?: EqualityFn<T>,
-): SessionState | null | T {
-  const storeSelector = useCallback(
-    (state: ReturnType<typeof useSessionStore.getState>): SessionState | null | T => {
-      const session = serverId ? (state.sessions[serverId] ?? null) : null;
-      return selector ? selector(session) : session;
-    },
-    [selector, serverId],
-  );
-
-  return useStoreWithEqualityFn(
-    useSessionStore,
-    storeSelector,
-    equalityFn as EqualityFn<SessionState | null | T>,
-  );
-}
--- a/packages/app/src/hooks/use-sidebar-workspaces-list.test.ts
+++ b/packages/app/src/hooks/use-sidebar-workspaces-list.test.ts
@@ -1,11 +1,15 @@
-import { describe, expect, it } from "vitest";
-import type { WorkspaceScriptPayload } from "@server/shared/messages";
+import { describe, expect, it, vi } from "vitest";
+
+vi.hoisted(() => {
+  (globalThis as unknown as { __DEV__: boolean }).__DEV__ = false;
+});
+
 import {
  appendMissingOrderKeys,
  applyStoredOrdering,
-  buildSidebarProjectsFromWorkspaces,
+  buildSidebarProjectsFromStructure,
 } from "./use-sidebar-workspaces-list";
-import type { WorkspaceDescriptor } from "@/stores/session-store";
+import type { WorkspaceStructureProject } from "@/stores/session-store-hooks";

 interface OrderedItem {
  key: string;
@@ -15,57 +19,22 @@ function item(key: string): OrderedItem {
  return { key };
 }

-function workspace(
-  input: Pick<WorkspaceDescriptor, "id" | "projectId" | "name" | "status"> &
-    Partial<
-      Pick<
-        WorkspaceDescriptor,
-        | "projectDisplayName"
-        | "projectRootPath"
-        | "workspaceDirectory"
-        | "projectKind"
-        | "workspaceKind"
-        | "scripts"
-      >
-    >,
-): WorkspaceDescriptor {
+function project(input: {
+  projectKey: string;
+  projectName?: string;
+  projectKind?: WorkspaceStructureProject["projectKind"];
+  iconWorkingDir?: string;
+  workspaceKeys: string[];
+}): WorkspaceStructureProject {
  return {
-    id: input.id,
-    projectId: input.projectId,
-    projectDisplayName: input.projectDisplayName ?? input.projectId,
-    projectRootPath: input.projectRootPath ?? input.id,
-    workspaceDirectory: input.workspaceDirectory ?? input.projectRootPath ?? input.id,
+    projectKey: input.projectKey,
+    projectName: input.projectName ?? input.projectKey,
    projectKind: input.projectKind ?? "git",
-    workspaceKind: input.workspaceKind ?? "checkout",
-    name: input.name,
-    status: input.status,
-    diffStat: null,
-    scripts: input.scripts ?? [],
+    iconWorkingDir: input.iconWorkingDir ?? input.projectKey,
+    workspaceKeys: input.workspaceKeys,
  };
 }

-const runningScript: WorkspaceScriptPayload = {
-  scriptName: "web",
-  type: "service",
-  hostname: "web.paseo.localhost",
-  port: 3000,
-  proxyUrl: "http://web.paseo.localhost:6767",
-  lifecycle: "running",
-  health: "healthy",
-  exitCode: null,
-};
-
-const stoppedScript: WorkspaceScriptPayload = {
-  scriptName: "api",
-  type: "service",
-  hostname: "api.paseo.localhost",
-  port: 3001,
-  proxyUrl: "http://api.paseo.localhost:6767",
-  lifecycle: "stopped",
-  health: null,
-  exitCode: null,
-};
-
 describe("applyStoredOrdering", () => {
  it("keeps unknown items on the baseline while applying stored order", () => {
    const result = applyStoredOrdering({
@@ -121,187 +90,52 @@ describe("appendMissingOrderKeys", () => {
  });
 });

-describe("buildSidebarProjectsFromWorkspaces", () => {
-  it("uses workspace descriptor name and status directly", () => {
-    const workspaces: WorkspaceDescriptor[] = [
-      workspace({
-        id: "/repo/main",
-        projectId: "project-1",
-        name: "feat/hard-cut",
-        status: "failed",
-      }),
-    ];
-
-    const projects = buildSidebarProjectsFromWorkspaces({
+describe("buildSidebarProjectsFromStructure", () => {
+  it("creates structural workspace rows from ordered workspace keys", () => {
+    const projects = buildSidebarProjectsFromStructure({
      serverId: "srv",
-      workspaces,
-      projectOrder: [],
-      workspaceOrderByScope: {},
+      projects: [
+        project({
+          projectKey: "project-1",
+          projectName: "Project 1",
+          iconWorkingDir: "/repo/main",
+          workspaceKeys: ["ws-main"],
+        }),
+      ],
    });

    expect(projects).toHaveLength(1);
-    expect(projects[0]?.statusBucket).toBe("failed");
-    expect(projects[0]?.workspaces[0]?.name).toBe("feat/hard-cut");
-    expect(projects[0]?.workspaces[0]?.statusBucket).toBe("failed");
+    expect(projects[0]?.projectName).toBe("Project 1");
+    expect(projects[0]?.workspaces[0]).toMatchObject({
+      workspaceKey: "srv:ws-main",
+      serverId: "srv",
+      workspaceId: "ws-main",
+      projectRootPath: "/repo/main",
+      projectKind: "git",
+    });
  });

-  it("threads scripts into workspace rows and derives hasRunningScripts", () => {
-    const projects = buildSidebarProjectsFromWorkspaces({
+  it("preserves the structure hook project order", () => {
+    const projects = buildSidebarProjectsFromStructure({
      serverId: "srv",
-      workspaces: [
-        workspace({
-          id: "/repo/main",
-          projectId: "project-1",
-          name: "main",
-          status: "running",
-          scripts: [runningScript, stoppedScript],
-        }),
+      projects: [
+        project({ projectKey: "project-b", workspaceKeys: ["ws-b"] }),
+        project({ projectKey: "project-a", workspaceKeys: ["ws-a"] }),
      ],
-      projectOrder: [],
-      workspaceOrderByScope: {},
    });

-    expect(projects[0]?.workspaces[0]?.scripts).toEqual([runningScript, stoppedScript]);
-    expect(projects[0]?.workspaces[0]?.hasRunningScripts).toBe(true);
+    expect(projects.map((project) => project.projectKey)).toEqual(["project-b", "project-a"]);
  });

-  it("preserves stored project order even when input order differs", () => {
-    const initialWorkspaces: WorkspaceDescriptor[] = [
-      workspace({
-        id: "/repo/b",
-        projectId: "project-b",
-        name: "feat/b",
-        status: "running",
-      }),
-      workspace({
-        id: "/repo/a",
-        projectId: "project-a",
-        name: "feat/a",
-        status: "running",
-      }),
-    ];
-
-    const seededOrder = appendMissingOrderKeys({
-      currentOrder: [],
-      visibleKeys: buildSidebarProjectsFromWorkspaces({
-        serverId: "srv",
-        workspaces: initialWorkspaces,
-        projectOrder: [],
-        workspaceOrderByScope: {},
-      }).map((project) => project.projectKey),
-    });
-
-    const updatedProjects = buildSidebarProjectsFromWorkspaces({
+  it("preserves the structure hook workspace order", () => {
+    const projects = buildSidebarProjectsFromStructure({
      serverId: "srv",
-      workspaces: [
-        workspace({
-          id: "/repo/a",
-          projectId: "project-a",
-          name: "feat/a",
-          status: "running",
-        }),
-        workspace({
-          id: "/repo/b",
-          projectId: "project-b",
-          name: "feat/b",
-          status: "running",
-        }),
-      ],
-      projectOrder: seededOrder,
-      workspaceOrderByScope: {},
-    });
-
-    expect(updatedProjects.map((project) => project.projectKey)).toEqual([
-      "project-a",
-      "project-b",
-    ]);
-  });
-
-  it("appends new projects after the stored project order", () => {
-    const projects = buildSidebarProjectsFromWorkspaces({
-      serverId: "srv",
-      workspaces: [
-        workspace({
-          id: "/repo/c",
-          projectId: "project-c",
-          name: "feat/c",
-          status: "running",
-        }),
-        workspace({
-          id: "/repo/b",
-          projectId: "project-b",
-          name: "feat/b",
-          status: "running",
-        }),
-        workspace({
-          id: "/repo/a",
-          projectId: "project-a",
-          name: "feat/a",
-          status: "running",
-        }),
-      ],
-      projectOrder: ["project-b", "project-a", "project-c"],
-      workspaceOrderByScope: {},
-    });
-
-    expect(projects.map((project) => project.projectKey)).toEqual([
-      "project-b",
-      "project-a",
-      "project-c",
-    ]);
-  });
-
-  it("preserves stored workspace order when workspace activity changes", () => {
-    const initialProjects = buildSidebarProjectsFromWorkspaces({
-      serverId: "srv",
-      workspaces: [
-        workspace({
-          id: "/repo/main",
-          projectId: "project-1",
-          name: "main",
-          status: "running",
-        }),
-        workspace({
-          id: "/repo/feature",
-          projectId: "project-1",
-          name: "feature",
-          status: "running",
-        }),
-      ],
-      projectOrder: ["project-1"],
-      workspaceOrderByScope: {},
-    });
-
-    const seededWorkspaceOrder = appendMissingOrderKeys({
-      currentOrder: [],
-      visibleKeys: initialProjects[0]?.workspaces.map((workspace) => workspace.workspaceKey) ?? [],
-    });
-
-    const projects = buildSidebarProjectsFromWorkspaces({
-      serverId: "srv",
-      workspaces: [
-        workspace({
-          id: "/repo/main",
-          projectId: "project-1",
-          name: "main",
-          status: "running",
-        }),
-        workspace({
-          id: "/repo/feature",
-          projectId: "project-1",
-          name: "feature",
-          status: "running",
-        }),
-      ],
-      projectOrder: ["project-1"],
-      workspaceOrderByScope: {
-        "srv::project-1": seededWorkspaceOrder,
-      },
+      projects: [project({ projectKey: "project-1", workspaceKeys: ["feature", "main"] })],
    });

    expect(projects[0]?.workspaces.map((workspace) => workspace.workspaceId)).toEqual([
-      "/repo/feature",
-      "/repo/main",
+      "feature",
+      "main",
    ]);
  });
 });
--- a/packages/app/src/hooks/use-sidebar-workspaces-list.ts
+++ b/packages/app/src/hooks/use-sidebar-workspaces-list.ts
@@ -6,13 +6,15 @@ import {
  useSessionStore,
  type WorkspaceDescriptor,
 } from "@/stores/session-store";
+import {
+  useWorkspaceStructure,
+  type WorkspaceStructureProject,
+} from "@/stores/session-store-hooks";
 import { getHostRuntimeStore } from "@/runtime/host-runtime";
 import { useSidebarOrderStore } from "@/stores/sidebar-order-store";
-import { projectDisplayNameFromProjectId } from "@/utils/project-display-name";

 const EMPTY_ORDER: string[] = [];
 const EMPTY_PROJECTS: SidebarProjectEntry[] = [];
-const EMPTY_WORKSPACE_ORDER_SCOPE: Record<string, string[]> = {};

 export type SidebarStateBucket = WorkspaceDescriptor["status"];

@@ -36,9 +38,6 @@ export interface SidebarProjectEntry {
  projectName: string;
  projectKind: WorkspaceDescriptor["projectKind"];
  iconWorkingDir: string;
-  statusBucket: SidebarStateBucket;
-  activeCount: number;
-  totalWorkspaces: number;
  workspaces: SidebarWorkspaceEntry[];
 }

@@ -50,119 +49,68 @@ export interface SidebarWorkspacesListResult {
  refreshAll: () => void;
 }

-const SIDEBAR_BUCKET_PRIORITY: Record<SidebarStateBucket, number> = {
-  done: 0,
-  attention: 1,
-  running: 2,
-  failed: 3,
-  needs_input: 4,
-};
-
-function aggregateBucket(
-  current: SidebarStateBucket,
-  candidate: SidebarStateBucket,
-): SidebarStateBucket {
-  return SIDEBAR_BUCKET_PRIORITY[candidate] > SIDEBAR_BUCKET_PRIORITY[current]
-    ? candidate
-    : current;
-}
-
-function compareWorkspaceBaseline(
-  left: SidebarWorkspaceEntry,
-  right: SidebarWorkspaceEntry,
-): number {
-  const nameDelta = left.name.localeCompare(right.name, undefined, {
-    numeric: true,
-    sensitivity: "base",
-  });
-  if (nameDelta !== 0) {
-    return nameDelta;
-  }
-
-  return left.workspaceId.localeCompare(right.workspaceId, undefined, {
-    sensitivity: "base",
-  });
-}
-
-function compareProjectBaseline(left: SidebarProjectEntry, right: SidebarProjectEntry): number {
-  return left.projectName.localeCompare(right.projectName, undefined, {
-    numeric: true,
-    sensitivity: "base",
-  });
-}
-
-export function buildSidebarProjectsFromWorkspaces(input: {
+function createStructuralWorkspaceEntry(input: {
  serverId: string;
-  workspaces: Iterable<WorkspaceDescriptor>;
-  projectOrder: string[];
-  workspaceOrderByScope: Record<string, string[]>;
+  project: WorkspaceStructureProject;
+  workspaceId: string;
+}): SidebarWorkspaceEntry {
+  return {
+    workspaceKey: `${input.serverId}:${input.workspaceId}`,
+    serverId: input.serverId,
+    workspaceId: input.workspaceId,
+    projectRootPath: input.project.iconWorkingDir,
+    workspaceDirectory: undefined,
+    projectKind: input.project.projectKind,
+    workspaceKind: "checkout",
+    name: input.workspaceId,
+    statusBucket: "done",
+    diffStat: null,
+    scripts: [],
+    hasRunningScripts: false,
+  };
+}
+
+export function createSidebarWorkspaceEntry(input: {
+  serverId: string;
+  workspace: WorkspaceDescriptor;
+}): SidebarWorkspaceEntry {
+  return {
+    workspaceKey: `${input.serverId}:${input.workspace.id}`,
+    serverId: input.serverId,
+    workspaceId: input.workspace.id,
+    projectRootPath: input.workspace.projectRootPath,
+    workspaceDirectory: input.workspace.workspaceDirectory,
+    projectKind: input.workspace.projectKind,
+    workspaceKind: input.workspace.workspaceKind,
+    name: input.workspace.name,
+    statusBucket: input.workspace.status,
+    diffStat: input.workspace.diffStat,
+    scripts: input.workspace.scripts,
+    hasRunningScripts: input.workspace.scripts.some((script) => script.lifecycle === "running"),
+  };
+}
+
+export function buildSidebarProjectsFromStructure(input: {
+  serverId: string;
+  projects: WorkspaceStructureProject[];
 }): SidebarProjectEntry[] {
-  const byProject = new Map<string, SidebarProjectEntry>();
-
-  for (const workspace of input.workspaces) {
-    const project =
-      byProject.get(workspace.projectId) ??
-      ({
-        projectKey: workspace.projectId,
-        projectName:
-          workspace.projectDisplayName || projectDisplayNameFromProjectId(workspace.projectId),
-        projectKind: workspace.projectKind,
-        iconWorkingDir: workspace.projectRootPath,
-        statusBucket: "done",
-        activeCount: 0,
-        totalWorkspaces: 0,
-        workspaces: [],
-      } satisfies SidebarProjectEntry);
-
-    const row: SidebarWorkspaceEntry = {
-      workspaceKey: `${input.serverId}:${workspace.id}`,
-      serverId: input.serverId,
-      workspaceId: workspace.id,
-      projectRootPath: workspace.projectRootPath,
-      workspaceDirectory: workspace.workspaceDirectory,
-      projectKind: workspace.projectKind,
-      workspaceKind: workspace.workspaceKind,
-      name: workspace.name,
-      statusBucket: workspace.status,
-      diffStat: workspace.diffStat,
-      scripts: workspace.scripts,
-      hasRunningScripts: workspace.scripts.some((script) => script.lifecycle === "running"),
-    };
-
-    project.workspaces.push(row);
-    project.totalWorkspaces += 1;
-    if (workspace.status !== "done") {
-      project.activeCount += 1;
-    }
-    project.statusBucket = aggregateBucket(project.statusBucket, workspace.status);
-
-    byProject.set(workspace.projectId, project);
+  if (input.projects.length === 0) {
+    return EMPTY_PROJECTS;
  }

-  const baselineProjects = Array.from(byProject.values()).map((project) => {
-    const baselineWorkspaces = [...project.workspaces];
-    baselineWorkspaces.sort(compareWorkspaceBaseline);
-
-    const workspaceOrderScopeKey = getWorkspaceOrderScopeKey(input.serverId, project.projectKey);
-    const orderedWorkspaces = applyStoredOrdering({
-      items: baselineWorkspaces,
-      storedOrder: input.workspaceOrderByScope[workspaceOrderScopeKey] ?? EMPTY_ORDER,
-      getKey: (workspace) => workspace.workspaceKey,
-    });
-
-    return {
-      ...project,
-      workspaces: orderedWorkspaces,
-    };
-  });
-
-  baselineProjects.sort(compareProjectBaseline);
-
-  return applyStoredOrdering({
-    items: baselineProjects,
-    storedOrder: input.projectOrder,
-    getKey: (project) => project.projectKey,
-  });
+  return input.projects.map((project) => ({
+    projectKey: project.projectKey,
+    projectName: project.projectName,
+    projectKind: project.projectKind,
+    iconWorkingDir: project.iconWorkingDir,
+    workspaces: project.workspaceKeys.map((workspaceId) =>
+      createStructuralWorkspaceEntry({
+        serverId: input.serverId,
+        project,
+        workspaceId,
+      }),
+    ),
+  }));
 }

 export function applyStoredOrdering<T>(input: {
@@ -229,10 +177,6 @@ export function appendMissingOrderKeys(input: {
  return [...input.currentOrder, ...missingKeys];
 }

-function getWorkspaceOrderScopeKey(serverId: string, projectKey: string): string {
-  return `${serverId.trim()}::${projectKey.trim()}`;
-}
-
 function toWorkspaceDescriptor(payload: WorkspaceDescriptorPayload): WorkspaceDescriptor {
  return normalizeWorkspaceDescriptor(payload);
 }
@@ -250,17 +194,12 @@ export function useSidebarWorkspacesList(options?: {
  const persistedProjectOrder = useSidebarOrderStore((state) =>
    serverId ? (state.projectOrderByServerId[serverId] ?? EMPTY_ORDER) : EMPTY_ORDER,
  );
-  const persistedWorkspaceOrderByScope = useSidebarOrderStore((state) =>
-    serverId ? state.workspaceOrderByServerAndProject : EMPTY_WORKSPACE_ORDER_SCOPE,
-  );

  const isActive = Boolean(serverId);
-  const sessionWorkspaces = useSessionStore((state) =>
-    isActive && serverId ? (state.sessions[serverId]?.workspaces ?? null) : null,
-  );
  const hasHydratedWorkspaces = useSessionStore((state) =>
    isActive && serverId ? (state.sessions[serverId]?.hasHydratedWorkspaces ?? false) : false,
  );
+  const workspaceStructure = useWorkspaceStructure(isActive ? serverId : null);

  const connectionStatus = useSyncExternalStore(
    (onStoreChange) =>
@@ -282,22 +221,20 @@ export function useSidebarWorkspacesList(options?: {
  );

  const projects = useMemo(() => {
-    if (!sessionWorkspaces || sessionWorkspaces.size === 0 || !serverId) {
+    if (!serverId || workspaceStructure.projects.length === 0) {
      return EMPTY_PROJECTS;
    }
-    return buildSidebarProjectsFromWorkspaces({
+    return buildSidebarProjectsFromStructure({
      serverId,
-      workspaces: sessionWorkspaces.values(),
-      projectOrder: persistedProjectOrder,
-      workspaceOrderByScope: persistedWorkspaceOrderByScope,
+      projects: workspaceStructure.projects,
    });
-  }, [persistedProjectOrder, persistedWorkspaceOrderByScope, serverId, sessionWorkspaces]);
+  }, [serverId, workspaceStructure]);

  useEffect(() => {
    if (!serverId) {
      return;
    }
-  }, [connectionStatus, hasHydratedWorkspaces, projects, serverId, sessionWorkspaces]);
+  }, [connectionStatus, hasHydratedWorkspaces, projects, serverId]);

  useEffect(() => {
    if (!serverId || projects.length === 0) {
@@ -313,9 +250,9 @@ export function useSidebarWorkspacesList(options?: {
    }

    for (const project of projects) {
-      const workspaceOrderScopeKey = getWorkspaceOrderScopeKey(serverId, project.projectKey);
-      const persistedWorkspaceOrder =
-        persistedWorkspaceOrderByScope[workspaceOrderScopeKey] ?? EMPTY_ORDER;
+      const persistedWorkspaceOrder = useSidebarOrderStore
+        .getState()
+        .getWorkspaceOrder(serverId, project.projectKey);
      const nextWorkspaceOrder = appendMissingOrderKeys({
        currentOrder: persistedWorkspaceOrder,
        visibleKeys: project.workspaces.map((workspace) => workspace.workspaceKey),
@@ -326,7 +263,7 @@ export function useSidebarWorkspacesList(options?: {
          .setWorkspaceOrder(serverId, project.projectKey, nextWorkspaceOrder);
      }
    }
-  }, [persistedProjectOrder, persistedWorkspaceOrderByScope, projects, serverId]);
+  }, [persistedProjectOrder, projects, serverId]);

  const refreshAll = useCallback(() => {
    if (!isActive || !serverId || connectionStatus !== "online") {
--- a/packages/app/src/panels/file-panel.tsx
+++ b/packages/app/src/panels/file-panel.tsx
@@ -1,12 +1,10 @@
-import { useMemo } from "react";
 import { Text, View } from "react-native";
 import { FileText } from "lucide-react-native";
 import invariant from "tiny-invariant";
 import { FilePane } from "@/components/file-pane";
 import { usePaneContext } from "@/panels/pane-context";
 import type { PanelRegistration } from "@/panels/panel-registry";
-import { useSessionStore } from "@/stores/session-store";
-import { resolveWorkspaceExecutionAuthority } from "@/utils/workspace-execution";
+import { useWorkspaceExecutionAuthority } from "@/stores/session-store-hooks";

 function useFilePanelDescriptor(target: { kind: "file"; path: string }) {
  const fileName = target.path.split("/").filter(Boolean).pop() ?? target.path;
@@ -21,25 +19,19 @@ function useFilePanelDescriptor(target: { kind: "file"; path: string }) {

 function FilePanel() {
  const { serverId, workspaceId, target } = usePaneContext();
-  const workspace = useSessionStore(
-    (state) => state.sessions[serverId]?.workspaces.get(workspaceId) ?? null,
-  );
-  const authority = useMemo(() => resolveWorkspaceExecutionAuthority({ workspace }), [workspace]);
+  const workspaceAuthority = useWorkspaceExecutionAuthority(serverId, workspaceId);
+  const workspaceDirectory = workspaceAuthority?.ok
+    ? workspaceAuthority.authority.workspaceDirectory
+    : null;
  invariant(target.kind === "file", "FilePanel requires file target");
-  if (!authority) {
+  if (!workspaceDirectory) {
    return (
      <View style={{ flex: 1, alignItems: "center", justifyContent: "center", padding: 16 }}>
        <Text>Workspace execution directory not found.</Text>
      </View>
    );
  }
-  return (
-    <FilePane
-      serverId={serverId}
-      workspaceRoot={authority.workspaceDirectory}
-      filePath={target.path}
-    />
-  );
+  return <FilePane serverId={serverId} workspaceRoot={workspaceDirectory} filePath={target.path} />;
 }

 export const filePanelRegistration: PanelRegistration<"file"> = {
--- a/packages/app/src/panels/terminal-panel.tsx
+++ b/packages/app/src/panels/terminal-panel.tsx
@@ -8,7 +8,7 @@ import { TerminalPane } from "@/components/terminal-pane";
 import { usePaneContext } from "@/panels/pane-context";
 import type { PanelDescriptor, PanelRegistration } from "@/panels/panel-registry";
 import { useSessionStore } from "@/stores/session-store";
-import { getWorkspaceExecutionAuthority } from "@/utils/workspace-execution";
+import { useWorkspaceExecutionAuthority } from "@/stores/session-store-hooks";

 type ListTerminalsPayload = ListTerminalsResponse["payload"];

@@ -25,11 +25,7 @@ function useTerminalPanelDescriptor(
  context: { serverId: string; workspaceId: string },
 ): PanelDescriptor {
  const client = useSessionStore((state) => state.sessions[context.serverId]?.client ?? null);
-  const workspaces = useSessionStore((state) => state.sessions[context.serverId]?.workspaces);
-  const workspaceAuthority = getWorkspaceExecutionAuthority({
-    workspaces,
-    workspaceId: context.workspaceId,
-  });
+  const workspaceAuthority = useWorkspaceExecutionAuthority(context.serverId, context.workspaceId)!;
  const workspaceDirectory = workspaceAuthority.ok
    ? workspaceAuthority.authority.workspaceDirectory
    : null;
@@ -63,8 +59,7 @@ function useTerminalPanelDescriptor(
 function TerminalPanel() {
  const isFocused = useIsFocused();
  const { serverId, workspaceId, target, isPaneFocused } = usePaneContext();
-  const workspaces = useSessionStore((state) => state.sessions[serverId]?.workspaces);
-  const workspaceAuthority = getWorkspaceExecutionAuthority({ workspaces, workspaceId });
+  const workspaceAuthority = useWorkspaceExecutionAuthority(serverId, workspaceId)!;
  const workspaceDirectory = workspaceAuthority.ok
    ? workspaceAuthority.authority.workspaceDirectory
    : null;
--- a/packages/app/src/runtime/host-runtime.test.ts
+++ b/packages/app/src/runtime/host-runtime.test.ts
@@ -12,6 +12,7 @@ import {
  HostRuntimeController,
  HostRuntimeStore,
  type HostRuntimeControllerDeps,
+  type HostRuntimeSnapshot,
 } from "./host-runtime";

 class FakeDaemonClient {
@@ -264,6 +265,27 @@ function clearProbeBackoff(controller: HostRuntimeController): void {
  ).connectionLastProbedAt.clear();
 }

+type HostRuntimeSnapshotPatch = Partial<Omit<HostRuntimeSnapshot, "serverId" | "clientGeneration">>;
+
+function updateControllerSnapshot(
+  controller: HostRuntimeController,
+  patch: HostRuntimeSnapshotPatch,
+): void {
+  (
+    controller as unknown as {
+      updateSnapshot: (patch: HostRuntimeSnapshotPatch) => void;
+    }
+  ).updateSnapshot(patch);
+}
+
+function makeProbeMap(
+  entries: Array<
+    [string, HostRuntimeSnapshot["probeByConnectionId"] extends Map<string, infer T> ? T : never]
+  >,
+): HostRuntimeSnapshot["probeByConnectionId"] {
+  return new Map(entries);
+}
+
 describe("HostRuntimeController", () => {
  it("keeps known hosts in connecting when a created client reports idle during connect", async () => {
    const host = makeHost({
@@ -923,6 +945,134 @@ describe("HostRuntimeController", () => {
    expect(controller.getSnapshot().clientGeneration).toBe(generationBeforeProbes);
    expect(createdClients).toHaveLength(0);
  });
+
+  it("does not notify or replace the snapshot for equal probe maps", () => {
+    const controller = new HostRuntimeController({ host: makeHost() });
+    const firstProbeMap = makeProbeMap([
+      ["direct:lan:6767", { status: "available", latencyMs: 12 }],
+    ]);
+    const equalProbeMap = makeProbeMap([
+      ["direct:lan:6767", { status: "available", latencyMs: 12 }],
+    ]);
+
+    updateControllerSnapshot(controller, { probeByConnectionId: firstProbeMap });
+    const snapshotAfterFirstProbe = controller.getSnapshot();
+    let notifyCount = 0;
+    const unsubscribe = controller.subscribe(() => {
+      notifyCount += 1;
+    });
+
+    updateControllerSnapshot(controller, { probeByConnectionId: equalProbeMap });
+
+    expect(notifyCount).toBe(0);
+    expect(controller.getSnapshot()).toBe(snapshotAfterFirstProbe);
+    expect(controller.getSnapshot().probeByConnectionId).toBe(firstProbeMap);
+    unsubscribe();
+  });
+
+  it("does not notify or replace the snapshot when connection status is already equal", () => {
+    const controller = new HostRuntimeController({ host: makeHost() });
+
+    updateControllerSnapshot(controller, { connectionStatus: "online" });
+    const snapshotAfterOnline = controller.getSnapshot();
+    let notifyCount = 0;
+    const unsubscribe = controller.subscribe(() => {
+      notifyCount += 1;
+    });
+
+    updateControllerSnapshot(controller, { connectionStatus: "online" });
+
+    expect(notifyCount).toBe(0);
+    expect(controller.getSnapshot()).toBe(snapshotAfterOnline);
+    unsubscribe();
+  });
+
+  it("does not notify or replace the snapshot when every patched field is equal", () => {
+    const controller = new HostRuntimeController({ host: makeHost() });
+    const firstProbeMap = makeProbeMap([
+      ["direct:lan:6767", { status: "available", latencyMs: 12 }],
+    ]);
+    const equalProbeMap = makeProbeMap([
+      ["direct:lan:6767", { status: "available", latencyMs: 12 }],
+    ]);
+
+    updateControllerSnapshot(controller, {
+      connectionStatus: "online",
+      probeByConnectionId: firstProbeMap,
+    });
+    const snapshotAfterSetup = controller.getSnapshot();
+    let notifyCount = 0;
+    const unsubscribe = controller.subscribe(() => {
+      notifyCount += 1;
+    });
+
+    updateControllerSnapshot(controller, {
+      connectionStatus: "online",
+      probeByConnectionId: equalProbeMap,
+    });
+
+    expect(notifyCount).toBe(0);
+    expect(controller.getSnapshot()).toBe(snapshotAfterSetup);
+    expect(controller.getSnapshot().probeByConnectionId).toBe(firstProbeMap);
+    unsubscribe();
+  });
+
+  it("notifies once for a changed field while preserving equal field identity", () => {
+    const controller = new HostRuntimeController({ host: makeHost() });
+    const firstProbeMap = makeProbeMap([
+      ["direct:lan:6767", { status: "available", latencyMs: 12 }],
+    ]);
+    const equalProbeMap = makeProbeMap([
+      ["direct:lan:6767", { status: "available", latencyMs: 12 }],
+    ]);
+
+    updateControllerSnapshot(controller, {
+      connectionStatus: "online",
+      probeByConnectionId: firstProbeMap,
+    });
+    const snapshotBeforeChange = controller.getSnapshot();
+    let notifyCount = 0;
+    const unsubscribe = controller.subscribe(() => {
+      notifyCount += 1;
+    });
+
+    updateControllerSnapshot(controller, {
+      connectionStatus: "offline",
+      probeByConnectionId: equalProbeMap,
+    });
+
+    expect(notifyCount).toBe(1);
+    expect(controller.getSnapshot()).not.toBe(snapshotBeforeChange);
+    expect(controller.getSnapshot().connectionStatus).toBe("offline");
+    expect(controller.getSnapshot().probeByConnectionId).toBe(firstProbeMap);
+    unsubscribe();
+  });
+
+  it("notifies once and replaces the probe map when probe contents change", () => {
+    const controller = new HostRuntimeController({ host: makeHost() });
+    const firstProbeMap = makeProbeMap([
+      ["direct:lan:6767", { status: "available", latencyMs: 12 }],
+    ]);
+    const changedProbeMap = makeProbeMap([
+      ["direct:lan:6767", { status: "available", latencyMs: 12 }],
+      ["relay:relay.paseo.sh:443", { status: "unavailable", latencyMs: null }],
+    ]);
+
+    updateControllerSnapshot(controller, { probeByConnectionId: firstProbeMap });
+    const snapshotBeforeChange = controller.getSnapshot();
+    let notifyCount = 0;
+    const unsubscribe = controller.subscribe(() => {
+      notifyCount += 1;
+    });
+
+    updateControllerSnapshot(controller, { probeByConnectionId: changedProbeMap });
+
+    expect(notifyCount).toBe(1);
+    expect(controller.getSnapshot()).not.toBe(snapshotBeforeChange);
+    expect(controller.getSnapshot().probeByConnectionId).toBe(changedProbeMap);
+    expect(controller.getSnapshot().probeByConnectionId).not.toBe(firstProbeMap);
+    unsubscribe();
+  });
 });

 describe("HostRuntimeStore", () => {
--- a/packages/app/src/runtime/host-runtime.ts
+++ b/packages/app/src/runtime/host-runtime.ts
@@ -1,5 +1,6 @@
 import { useSyncExternalStore, useCallback, useMemo } from "react";
 import AsyncStorage from "@react-native-async-storage/async-storage";
+import equal from "fast-deep-equal/es6";
 import {
  DaemonClient,
  type ConnectionState,
@@ -67,6 +68,16 @@ export type HostRuntimeSnapshot = {
  clientGeneration: number;
 };

+type HostRuntimeSnapshotPatch = Partial<Omit<HostRuntimeSnapshot, "serverId" | "clientGeneration">>;
+
+function setSnapshotPatchField<Key extends keyof HostRuntimeSnapshotPatch>(
+  patch: HostRuntimeSnapshotPatch,
+  key: Key,
+  value: HostRuntimeSnapshot[Key],
+): void {
+  patch[key] = value;
+}
+
 export function isHostRuntimeConnected(snapshot: HostRuntimeSnapshot | null): boolean {
  return snapshot?.connectionStatus === "online";
 }
@@ -831,15 +842,25 @@ export class HostRuntimeController {
    });
  }

-  private updateSnapshot(
-    patch: Partial<Omit<HostRuntimeSnapshot, "serverId" | "clientGeneration">>,
-  ): void {
-    const next: HostRuntimeSnapshot = {
+  private updateSnapshot(patch: HostRuntimeSnapshotPatch): void {
+    const preservedPatch: HostRuntimeSnapshotPatch = { ...patch };
+    let hasChanged = this.host.serverId !== this.snapshot.serverId;
+    for (const key of Object.keys(patch) as Array<keyof HostRuntimeSnapshotPatch>) {
+      const incomingValue = patch[key];
+      if (equal(this.snapshot[key], incomingValue)) {
+        setSnapshotPatchField(preservedPatch, key, this.snapshot[key]);
+        continue;
+      }
+      hasChanged = true;
+    }
+    if (!hasChanged) {
+      return;
+    }
+    this.snapshot = {
      ...this.snapshot,
-      ...patch,
+      ...preservedPatch,
      serverId: this.host.serverId,
    };
-    this.snapshot = next;
    for (const listener of this.listeners) {
      listener();
    }
@@ -1021,7 +1042,7 @@ export class HostRuntimeController {
        state,
        lastError: client.lastError,
      });
-      const patch: Partial<Omit<HostRuntimeSnapshot, "serverId" | "clientGeneration">> = {
+      const patch: HostRuntimeSnapshotPatch = {
        ...toSnapshotConnectionPatch(this.connectionMachineState),
      };

--- a/packages/app/src/screens/open-project-screen.tsx
+++ b/packages/app/src/screens/open-project-screen.tsx
@@ -8,6 +8,7 @@ import { MenuHeader } from "@/components/headers/menu-header";
 import { useOpenProjectPicker } from "@/hooks/use-open-project-picker";
 import { usePanelStore } from "@/stores/panel-store";
 import { useSessionStore } from "@/stores/session-store";
+import { useHasWorkspaces } from "@/stores/session-store-hooks";
 import {
  useIsCompactFormFactor,
  HEADER_INNER_HEIGHT,
@@ -22,7 +23,7 @@ export function OpenProjectScreen({ serverId }: { serverId: string }) {
  const openAgentList = usePanelStore((s) => s.openAgentList);
  const openProjectPicker = useOpenProjectPicker(serverId);
  const hasHydrated = useSessionStore((s) => s.sessions[serverId]?.hasHydratedWorkspaces ?? false);
-  const hasProjects = useSessionStore((s) => (s.sessions[serverId]?.workspaces?.size ?? 0) > 0);
+  const hasProjects = useHasWorkspaces(serverId);
  const isLocalDaemon = useIsLocalDaemon(serverId);
  const [isPairDeviceOpen, setIsPairDeviceOpen] = useState(false);

--- a/packages/app/src/screens/workspace/workspace-draft-agent-tab.tsx
+++ b/packages/app/src/screens/workspace/workspace-draft-agent-tab.tsx
@@ -11,9 +11,9 @@ import { useDraftAgentCreateFlow } from "@/hooks/use-draft-agent-create-flow";
 import { useHostRuntimeClient, useHostRuntimeIsConnected } from "@/runtime/host-runtime";
 import { buildWorkspaceDraftAgentConfig } from "@/screens/workspace/workspace-draft-agent-config";
 import { buildDraftStoreKey } from "@/stores/draft-keys";
-import { type Agent, useSessionStore } from "@/stores/session-store";
+import type { Agent } from "@/stores/session-store";
+import { useWorkspaceExecutionAuthority } from "@/stores/session-store-hooks";
 import { encodeImages } from "@/utils/encode-images";
-import { getWorkspaceExecutionAuthority } from "@/utils/workspace-execution";
 import { shouldAutoFocusWorkspaceDraftComposer } from "@/screens/workspace/workspace-draft-pane-focus";
 import type { AgentCapabilityFlags } from "@server/server/agent/agent-sdk-types";
 import type { AgentSnapshotPayload } from "@server/shared/messages";
@@ -50,9 +50,8 @@ export function WorkspaceDraftAgentTab({
 }: WorkspaceDraftAgentTabProps) {
  const client = useHostRuntimeClient(serverId);
  const isConnected = useHostRuntimeIsConnected(serverId);
-  const workspaces = useSessionStore((state) => state.sessions[serverId]?.workspaces);
-  const workspaceAuthority = getWorkspaceExecutionAuthority({ workspaces, workspaceId });
-  const workspaceExecutionAuthority = workspaceAuthority.ok ? workspaceAuthority.authority : null;
+  const workspaceAuthority = useWorkspaceExecutionAuthority(serverId, workspaceId);
+  const workspaceExecutionAuthority = workspaceAuthority?.ok ? workspaceAuthority.authority : null;
  const workspaceDirectory = workspaceExecutionAuthority?.workspaceDirectory ?? null;
  const addImagesRef = useRef<((images: ImageAttachment[]) => void) | null>(null);
  const draftStoreKey = useMemo(
--- a/packages/app/src/screens/workspace/workspace-screen.tsx
+++ b/packages/app/src/screens/workspace/workspace-screen.tsx
@@ -66,6 +66,7 @@ import {
 import { useHostRuntimeClient, useHostRuntimeIsConnected } from "@/runtime/host-runtime";
 import { useProvidersSnapshot } from "@/hooks/use-providers-snapshot";
 import { useWorkspaceSetupStore } from "@/stores/workspace-setup-store";
+import { useWorkspace } from "@/stores/session-store-hooks";
 import { useWorkspaceTerminalSessionRetention } from "@/terminal/hooks/use-workspace-terminal-session-retention";
 import {
  checkoutStatusQueryKey,
@@ -79,7 +80,7 @@ import { useStableEvent } from "@/hooks/use-stable-event";
 import { buildProviderCommand } from "@/utils/provider-command-templates";
 import { generateDraftId } from "@/stores/draft-keys";
 import {
-  resolveWorkspaceExecutionAuthority,
+  getWorkspaceExecutionAuthority,
  resolveWorkspaceRouteId,
 } from "@/utils/workspace-execution";
 import {
@@ -617,9 +618,7 @@ function WorkspaceScreenContent({ serverId, workspaceId }: WorkspaceScreenProps)
    resolveWorkspaceRouteId({
      routeWorkspaceId: workspaceId,
    }) ?? "";
-  const sessionWorkspaces = useSessionStore(
-    (state) => state.sessions[normalizedServerId]?.workspaces,
-  );
+  const workspaceDescriptor = useWorkspace(normalizedServerId, normalizedWorkspaceId);

  const workspaceTerminalScopeKey =
    normalizedServerId && normalizedWorkspaceId
@@ -632,17 +631,18 @@ function WorkspaceScreenContent({ serverId, workspaceId }: WorkspaceScreenProps)
  const queryClient = useQueryClient();
  const client = useHostRuntimeClient(normalizedServerId);
  const isConnected = useHostRuntimeIsConnected(normalizedServerId);
-  const workspaceDescriptor = sessionWorkspaces?.get(normalizedWorkspaceId) ?? null;
  const workspaceAuthority = useMemo(
    () =>
-      resolveWorkspaceExecutionAuthority({
-        workspaces: sessionWorkspaces,
-        workspaceId: normalizedWorkspaceId,
+      getWorkspaceExecutionAuthority({
+        workspace: workspaceDescriptor,
      }),
-    [normalizedWorkspaceId, sessionWorkspaces],
+    [workspaceDescriptor],
+  );
+  const workspaceExecutionAuthority = workspaceAuthority.ok ? workspaceAuthority.authority : null;
+  const workspaceDirectory = workspaceExecutionAuthority?.workspaceDirectory ?? null;
+  const isMissingWorkspaceExecutionAuthority = Boolean(
+    workspaceDescriptor && !workspaceExecutionAuthority,
  );
-  const workspaceDirectory = workspaceAuthority?.workspaceDirectory ?? null;
-  const isMissingWorkspaceExecutionAuthority = Boolean(workspaceDescriptor && !workspaceAuthority);

  // Warm the server-side provider snapshot for this workspace cwd so the model
  // picker is ready when opened. Consumers share the same query cache key.
--- a/packages/app/src/screens/workspace/workspace-source-of-truth.test.ts
+++ b/packages/app/src/screens/workspace/workspace-source-of-truth.test.ts
@@ -1,9 +1,14 @@
-import { describe, expect, it } from "vitest";
+import { describe, expect, it, vi } from "vitest";
+
+vi.hoisted(() => {
+  (globalThis as unknown as { __DEV__: boolean }).__DEV__ = false;
+});
+
 import {
  resolveWorkspaceHeader,
  shouldRenderMissingWorkspaceDescriptor,
 } from "./workspace-header-source";
-import { buildSidebarProjectsFromWorkspaces } from "@/hooks/use-sidebar-workspaces-list";
+import { createSidebarWorkspaceEntry } from "@/hooks/use-sidebar-workspaces-list";
 import type { WorkspaceDescriptor } from "@/stores/session-store";

 describe("workspace source of truth consumption", () => {
@@ -23,17 +28,15 @@ describe("workspace source of truth consumption", () => {
    };

    const header = resolveWorkspaceHeader({ workspace });
-    const sidebarProjects = buildSidebarProjectsFromWorkspaces({
+    const sidebarWorkspace = createSidebarWorkspaceEntry({
      serverId: "srv",
-      workspaces: [workspace],
-      projectOrder: [],
-      workspaceOrderByScope: {},
+      workspace,
    });

    expect(header.title).toBe("feat/workspace-sot");
    expect(header.subtitle).toBe("getpaseo/paseo");
-    expect(sidebarProjects[0]?.workspaces[0]?.name).toBe(header.title);
-    expect(sidebarProjects[0]?.workspaces[0]?.statusBucket).toBe("running");
+    expect(sidebarWorkspace.name).toBe(header.title);
+    expect(sidebarWorkspace.statusBucket).toBe("running");
  });

  it("renders explicit missing state only after workspace hydration", () => {
--- a/packages/app/src/stores/session-store-hooks.test.ts
+++ b/packages/app/src/stores/session-store-hooks.test.ts
@@ -0,0 +1,364 @@
+/**
+ * @vitest-environment jsdom
+ */
+import { act, renderHook } from "@testing-library/react";
+import { afterEach, describe, expect, it } from "vitest";
+
+import type { DaemonClient } from "@server/client/daemon-client";
+import {
+  useHasWorkspaces,
+  useRecommendedProjectPaths,
+  useResolveWorkspaceIdByCwd,
+  useWorkspace,
+  useWorkspaceExecutionAuthority,
+  useWorkspaceFields,
+  useWorkspaceKeys,
+  useWorkspaceStatusesForBadges,
+  useWorkspaceStructure,
+} from "./session-store-hooks";
+import { useSidebarOrderStore } from "./sidebar-order-store";
+import { useSessionStore, type WorkspaceDescriptor } from "./session-store";
+
+const SERVER_ID = "test-server";
+
+function createWorkspace(
+  input: Partial<WorkspaceDescriptor> & Pick<WorkspaceDescriptor, "id">,
+): WorkspaceDescriptor {
+  return {
+    id: input.id,
+    projectId: input.projectId ?? "project-1",
+    projectDisplayName: input.projectDisplayName ?? "Project 1",
+    projectRootPath: input.projectRootPath ?? "/repo",
+    workspaceDirectory: input.workspaceDirectory ?? "/repo",
+    projectKind: input.projectKind ?? "git",
+    workspaceKind: input.workspaceKind ?? "local_checkout",
+    name: input.name ?? "main",
+    status: input.status ?? "done",
+    diffStat: input.diffStat ?? null,
+    scripts: input.scripts ?? [],
+  };
+}
+
+function initializeWorkspaces(workspaces: WorkspaceDescriptor[]): void {
+  act(() => {
+    useSessionStore.getState().initializeSession(SERVER_ID, null as unknown as DaemonClient);
+    useSessionStore
+      .getState()
+      .setWorkspaces(SERVER_ID, new Map(workspaces.map((workspace) => [workspace.id, workspace])));
+  });
+}
+
+afterEach(() => {
+  act(() => {
+    useSessionStore.getState().clearSession(SERVER_ID);
+    useSidebarOrderStore.setState({
+      projectOrderByServerId: {},
+      workspaceOrderByServerAndProject: {},
+    });
+  });
+});
+
+describe("useWorkspace", () => {
+  it("resolves a descriptor when the route id matches workspace identity but not the map key", () => {
+    const workspace = createWorkspace({ id: "workspace-a" });
+    act(() => {
+      useSessionStore.getState().initializeSession(SERVER_ID, null as unknown as DaemonClient);
+      useSessionStore.getState().setWorkspaces(SERVER_ID, new Map([["map-key-a", workspace]]));
+    });
+
+    const { result } = renderHook(() => useWorkspace(SERVER_ID, workspace.id));
+
+    expect(result.current).toBe(workspace);
+  });
+
+  it("keeps the descriptor reference for unrelated workspace updates", () => {
+    const workspaceA = createWorkspace({ id: "workspace-a", name: "A" });
+    const workspaceB = createWorkspace({ id: "workspace-b", name: "B" });
+    initializeWorkspaces([workspaceA, workspaceB]);
+
+    const { result } = renderHook(() => useWorkspace(SERVER_ID, workspaceA.id));
+    const before = result.current;
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [{ ...workspaceB, status: "running" }]);
+    });
+    expect(result.current).toBe(before);
+
+    act(() => {
+      useSessionStore
+        .getState()
+        .mergeWorkspaces(SERVER_ID, [{ ...workspaceA, status: "attention" }]);
+    });
+    expect(result.current).not.toBe(before);
+  });
+
+  it("keeps the descriptor reference when the observed workspace is rewritten with content-equal data", () => {
+    const workspace = createWorkspace({ id: "workspace-a", scripts: [] });
+    initializeWorkspaces([workspace]);
+
+    const { result } = renderHook(() => useWorkspace(SERVER_ID, workspace.id));
+    const before = result.current;
+
+    act(() => {
+      useSessionStore
+        .getState()
+        .setWorkspaces(SERVER_ID, new Map([[workspace.id, { ...workspace, scripts: [] }]]));
+    });
+    expect(result.current).toBe(before);
+  });
+});
+
+describe("useWorkspaceExecutionAuthority", () => {
+  it("preserves the old missing-workspace message with the requested id", () => {
+    initializeWorkspaces([]);
+
+    const { result } = renderHook(() => useWorkspaceExecutionAuthority(SERVER_ID, "missing-id"));
+
+    expect(result.current).toMatchObject({
+      ok: false,
+      message: "Workspace not found: missing-id",
+    });
+  });
+
+  it("keeps deep-equal authority references under unrelated workspace updates", () => {
+    const workspaceA = createWorkspace({ id: "workspace-a", name: "A" });
+    const workspaceB = createWorkspace({ id: "workspace-b", name: "B" });
+    initializeWorkspaces([workspaceA, workspaceB]);
+
+    const { result } = renderHook(() => useWorkspaceExecutionAuthority(SERVER_ID, workspaceA.id));
+    const before = result.current;
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [{ ...workspaceB, status: "running" }]);
+    });
+
+    expect(result.current).toBe(before);
+  });
+});
+
+describe("useWorkspaceFields", () => {
+  it("keeps deep-equal projection references until projected fields change", () => {
+    const workspace = createWorkspace({ id: "workspace-a", name: "A", status: "done" });
+    initializeWorkspaces([workspace]);
+
+    const { result } = renderHook(() =>
+      useWorkspaceFields(SERVER_ID, workspace.id, (current) => ({
+        identity: {
+          id: current.id,
+          name: current.name,
+        },
+      })),
+    );
+    const before = result.current;
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [{ ...workspace, status: "running" }]);
+    });
+    expect(result.current).toBe(before);
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [
+        {
+          ...workspace,
+          name: "A renamed",
+          status: "running",
+        },
+      ]);
+    });
+    expect(result.current).not.toBe(before);
+  });
+});
+
+describe("useWorkspaceStructure", () => {
+  it("changes for membership updates but not status-only updates", () => {
+    const workspaceA = createWorkspace({ id: "workspace-a", name: "A" });
+    const workspaceB = createWorkspace({ id: "workspace-b", name: "B" });
+    initializeWorkspaces([workspaceA]);
+
+    const { result } = renderHook(() => useWorkspaceStructure(SERVER_ID));
+    const before = result.current;
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [workspaceB]);
+    });
+    const afterAdd = result.current;
+    expect(afterAdd).not.toBe(before);
+    expect(afterAdd.projects[0]?.workspaceKeys).toEqual(["workspace-a", "workspace-b"]);
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [{ ...workspaceA, status: "running" }]);
+    });
+    expect(result.current).toBe(afterAdd);
+  });
+
+  it("changes when a structure-relevant project identity field changes", () => {
+    const workspace = createWorkspace({
+      id: "workspace-a",
+      projectDisplayName: "Project 1",
+    });
+    initializeWorkspaces([workspace]);
+
+    const { result } = renderHook(() => useWorkspaceStructure(SERVER_ID));
+    const before = result.current;
+
+    act(() => {
+      useSessionStore
+        .getState()
+        .mergeWorkspaces(SERVER_ID, [{ ...workspace, projectDisplayName: "Project Renamed" }]);
+    });
+    expect(result.current).not.toBe(before);
+  });
+
+  it("changes when persisted sidebar project order changes", () => {
+    const workspaceA = createWorkspace({
+      id: "workspace-a",
+      projectId: "project-a",
+      projectDisplayName: "Project A",
+    });
+    const workspaceB = createWorkspace({
+      id: "workspace-b",
+      projectId: "project-b",
+      projectDisplayName: "Project B",
+    });
+    initializeWorkspaces([workspaceA, workspaceB]);
+
+    const { result } = renderHook(() => useWorkspaceStructure(SERVER_ID));
+    const before = result.current;
+
+    act(() => {
+      useSidebarOrderStore.getState().setProjectOrder(SERVER_ID, ["project-b", "project-a"]);
+    });
+    expect(result.current).not.toBe(before);
+  });
+});
+
+describe("useWorkspaceKeys", () => {
+  it("changes for reorder updates but not content-only updates", () => {
+    const workspaceA = createWorkspace({ id: "workspace-a", name: "A" });
+    const workspaceB = createWorkspace({ id: "workspace-b", name: "B" });
+    initializeWorkspaces([workspaceA, workspaceB]);
+
+    const { result } = renderHook(() => useWorkspaceKeys(SERVER_ID));
+    const before = result.current;
+    expect(before).toEqual(["workspace-a", "workspace-b"]);
+
+    act(() => {
+      useSessionStore.getState().setWorkspaces(
+        SERVER_ID,
+        new Map([
+          [workspaceB.id, workspaceB],
+          [workspaceA.id, workspaceA],
+        ]),
+      );
+    });
+    const afterReorder = result.current;
+    expect(afterReorder).not.toBe(before);
+    expect(afterReorder).toEqual(["workspace-b", "workspace-a"]);
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [{ ...workspaceA, status: "running" }]);
+    });
+    expect(result.current).toBe(afterReorder);
+  });
+});
+
+describe("useRecommendedProjectPaths", () => {
+  it("updates when an existing workspace project root changes", () => {
+    const workspace = createWorkspace({ id: "workspace-a", projectRootPath: "/repo/a" });
+    initializeWorkspaces([workspace]);
+
+    const { result } = renderHook(() => useRecommendedProjectPaths(SERVER_ID));
+
+    act(() => {
+      useSessionStore
+        .getState()
+        .mergeWorkspaces(SERVER_ID, [{ ...workspace, projectRootPath: "/repo/b" }]);
+    });
+
+    expect(result.current).toEqual(["/repo/b"]);
+  });
+
+  it("keeps the path list reference under unrelated workspace updates", () => {
+    const workspace = createWorkspace({ id: "workspace-a", projectRootPath: "/repo/a" });
+    initializeWorkspaces([workspace]);
+
+    const { result } = renderHook(() => useRecommendedProjectPaths(SERVER_ID));
+    const before = result.current;
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [{ ...workspace, status: "running" }]);
+    });
+
+    expect(result.current).toBe(before);
+  });
+});
+
+describe("useHasWorkspaces", () => {
+  it("stays stable when workspace membership changes without flipping the boolean", () => {
+    const workspaceA = createWorkspace({ id: "workspace-a" });
+    const workspaceB = createWorkspace({ id: "workspace-b" });
+    initializeWorkspaces([workspaceA]);
+
+    const { result } = renderHook(() => useHasWorkspaces(SERVER_ID));
+    const before = result.current;
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [workspaceB]);
+    });
+
+    expect(result.current).toBe(before);
+  });
+});
+
+describe("useResolveWorkspaceIdByCwd", () => {
+  it("resolves by cwd and stays stable under unrelated updates", () => {
+    const workspaceA = createWorkspace({
+      id: "workspace-a",
+      workspaceDirectory: "/repo/a",
+    });
+    const workspaceB = createWorkspace({
+      id: "workspace-b",
+      workspaceDirectory: "/repo/b",
+    });
+    initializeWorkspaces([workspaceA, workspaceB]);
+
+    const { result } = renderHook(() => useResolveWorkspaceIdByCwd(SERVER_ID, "/repo/a"));
+    const before = result.current;
+    expect(before).toBe("workspace-a");
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [{ ...workspaceB, status: "running" }]);
+    });
+    expect(result.current).toBe(before);
+  });
+});
+
+describe("useWorkspaceStatusesForBadges", () => {
+  it("tracks status changes without changing for no-ops or unrelated descriptor updates", () => {
+    const workspaceA = createWorkspace({ id: "workspace-a", status: "done" });
+    const workspaceB = createWorkspace({ id: "workspace-b", status: "attention" });
+    initializeWorkspaces([workspaceA, workspaceB]);
+
+    const { result } = renderHook(() => useWorkspaceStatusesForBadges());
+    const before = result.current;
+    expect(before).toEqual(["done", "attention"]);
+
+    act(() => {
+      useSessionStore
+        .getState()
+        .mergeWorkspaces(SERVER_ID, [{ ...workspaceA, scripts: [...workspaceA.scripts] }]);
+    });
+    expect(result.current).toBe(before);
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [{ ...workspaceB, name: "Renamed" }]);
+    });
+    expect(result.current).toBe(before);
+
+    act(() => {
+      useSessionStore.getState().mergeWorkspaces(SERVER_ID, [{ ...workspaceA, status: "failed" }]);
+    });
+    expect(result.current).not.toBe(before);
+    expect(result.current).toEqual(["failed", "attention"]);
+  });
+});
--- a/packages/app/src/stores/session-store-hooks.ts
+++ b/packages/app/src/stores/session-store-hooks.ts
@@ -0,0 +1,384 @@
+import equal from "fast-deep-equal";
+import { useMemo } from "react";
+import { useStoreWithEqualityFn } from "zustand/traditional";
+import { useSidebarOrderStore } from "@/stores/sidebar-order-store";
+import { projectDisplayNameFromProjectId } from "@/utils/project-display-name";
+import type { DesktopBadgeWorkspaceStatus } from "@/utils/desktop-badge-state";
+import {
+  getWorkspaceExecutionAuthority,
+  resolveWorkspaceIdByExecutionDirectory,
+  resolveWorkspaceMapKeyByIdentity,
+  type WorkspaceExecutionAuthorityResult,
+} from "@/utils/workspace-execution";
+import { useSessionStore, type WorkspaceDescriptor } from "./session-store";
+
+// These are the ONLY supported ways to read workspaces from the session store.
+// Do not write raw `useSessionStore` selectors that return the workspaces Map, a session object,
+// or the sessions dict — it breaks re-render isolation.
+
+export type { DesktopBadgeWorkspaceStatus } from "@/utils/desktop-badge-state";
+
+export interface WorkspaceStructureProject {
+  projectKey: string;
+  projectName: string;
+  projectKind: WorkspaceDescriptor["projectKind"];
+  iconWorkingDir: string;
+  workspaceKeys: string[];
+}
+
+export interface WorkspaceStructure {
+  projects: WorkspaceStructureProject[];
+}
+
+type SessionStoreSnapshot = ReturnType<typeof useSessionStore.getState>;
+
+const EMPTY_WORKSPACE_KEYS: string[] = [];
+const EMPTY_WORKSPACE_STRUCTURE: WorkspaceStructure = { projects: [] };
+
+function getWorkspaceOrderScopeKey(serverId: string, projectKey: string): string {
+  return `${serverId.trim()}::${projectKey.trim()}`;
+}
+
+function compareWorkspaceStructureItems(
+  left: { workspaceId: string; workspaceName: string },
+  right: { workspaceId: string; workspaceName: string },
+): number {
+  const nameDelta = left.workspaceName.localeCompare(right.workspaceName, undefined, {
+    numeric: true,
+    sensitivity: "base",
+  });
+  if (nameDelta !== 0) {
+    return nameDelta;
+  }
+
+  return left.workspaceId.localeCompare(right.workspaceId, undefined, {
+    sensitivity: "base",
+  });
+}
+
+function compareWorkspaceStructureProjects(
+  left: WorkspaceStructureProject,
+  right: WorkspaceStructureProject,
+): number {
+  return left.projectName.localeCompare(right.projectName, undefined, {
+    numeric: true,
+    sensitivity: "base",
+  });
+}
+
+function applyStoredOrdering<T>(input: {
+  items: T[];
+  storedOrder: readonly string[];
+  getKey: (item: T) => string;
+}): T[] {
+  if (input.items.length <= 1 || input.storedOrder.length === 0) {
+    return input.items;
+  }
+
+  const itemByKey = new Map<string, T>();
+  for (const item of input.items) {
+    itemByKey.set(input.getKey(item), item);
+  }
+
+  const prunedOrder: string[] = [];
+  const seen = new Set<string>();
+  for (const key of input.storedOrder) {
+    if (!itemByKey.has(key) || seen.has(key)) {
+      continue;
+    }
+    seen.add(key);
+    prunedOrder.push(key);
+  }
+
+  if (prunedOrder.length === 0) {
+    return input.items;
+  }
+
+  const orderedSet = new Set(prunedOrder);
+  const ordered: T[] = [];
+  let orderedIndex = 0;
+
+  for (const item of input.items) {
+    const key = input.getKey(item);
+    if (!orderedSet.has(key)) {
+      ordered.push(item);
+      continue;
+    }
+
+    const targetKey = prunedOrder[orderedIndex] ?? key;
+    orderedIndex += 1;
+    ordered.push(itemByKey.get(targetKey) ?? item);
+  }
+
+  return ordered;
+}
+
+function selectWorkspace(
+  state: SessionStoreSnapshot,
+  serverId: string | null,
+  workspaceId: string | null,
+): WorkspaceDescriptor | null {
+  if (!serverId || !workspaceId) {
+    return null;
+  }
+  const workspaces = state.sessions[serverId]?.workspaces;
+  const workspaceKey = resolveWorkspaceMapKeyByIdentity({
+    workspaces,
+    workspaceId,
+  });
+  return workspaceKey ? (workspaces?.get(workspaceKey) ?? null) : null;
+}
+
+export function useWorkspace(
+  serverId: string | null,
+  workspaceId: string | null,
+): WorkspaceDescriptor | null {
+  return useStoreWithEqualityFn(
+    useSessionStore,
+    (state) => selectWorkspace(state, serverId, workspaceId),
+    Object.is,
+  );
+}
+
+export function useWorkspaceFields<T>(
+  serverId: string | null,
+  workspaceId: string | null,
+  project: (w: WorkspaceDescriptor) => T,
+): T | null {
+  return useStoreWithEqualityFn(
+    useSessionStore,
+    (state) => {
+      const workspace = selectWorkspace(state, serverId, workspaceId);
+      return workspace ? project(workspace) : null;
+    },
+    equal,
+  );
+}
+
+export function useWorkspaceExecutionAuthority(
+  serverId: string | null,
+  workspaceId: string | null,
+): WorkspaceExecutionAuthorityResult | null {
+  return useStoreWithEqualityFn(
+    useSessionStore,
+    (state) => {
+      if (serverId === null || workspaceId === null) {
+        return null;
+      }
+      return getWorkspaceExecutionAuthority({
+        workspaces: state.sessions[serverId]?.workspaces,
+        workspaceId,
+      });
+    },
+    equal,
+  );
+}
+
+function selectWorkspaceStructureProjects(
+  state: SessionStoreSnapshot,
+  serverId: string | null,
+): WorkspaceStructureProject[] {
+  if (!serverId) {
+    return EMPTY_WORKSPACE_STRUCTURE.projects;
+  }
+
+  const workspaces = state.sessions[serverId]?.workspaces;
+  if (!workspaces || workspaces.size === 0) {
+    return EMPTY_WORKSPACE_STRUCTURE.projects;
+  }
+
+  const byProject = new Map<
+    string,
+    WorkspaceStructureProject & {
+      workspaces: Array<{ workspaceId: string; workspaceName: string; workspaceKey: string }>;
+    }
+  >();
+
+  for (const workspace of workspaces.values()) {
+    const project =
+      byProject.get(workspace.projectId) ??
+      ({
+        projectKey: workspace.projectId,
+        projectName:
+          workspace.projectDisplayName || projectDisplayNameFromProjectId(workspace.projectId),
+        projectKind: workspace.projectKind,
+        iconWorkingDir: workspace.projectRootPath,
+        workspaceKeys: [],
+        workspaces: [],
+      } satisfies WorkspaceStructureProject & {
+        workspaces: Array<{ workspaceId: string; workspaceName: string; workspaceKey: string }>;
+      });
+
+    project.workspaces.push({
+      workspaceId: workspace.id,
+      workspaceName: workspace.name,
+      workspaceKey: `${serverId}:${workspace.id}`,
+    });
+    byProject.set(workspace.projectId, project);
+  }
+
+  const projects = Array.from(byProject.values()).map(
+    ({ workspaces: projectWorkspaces, ...project }) => {
+      const sortedWorkspaces = [...projectWorkspaces].sort(compareWorkspaceStructureItems);
+
+      return {
+        ...project,
+        workspaceKeys: sortedWorkspaces.map((workspace) => workspace.workspaceId),
+      };
+    },
+  );
+
+  projects.sort(compareWorkspaceStructureProjects);
+  return projects;
+}
+
+function selectWorkspaceOrderByScopeForServer(
+  workspaceOrderByScope: Record<string, string[]>,
+  serverId: string | null,
+): Record<string, string[]> {
+  if (!serverId) {
+    return {};
+  }
+  const prefix = `${serverId.trim()}::`;
+  const relevantOrderByScope: Record<string, string[]> = {};
+  for (const [scopeKey, order] of Object.entries(workspaceOrderByScope)) {
+    if (scopeKey.startsWith(prefix)) {
+      relevantOrderByScope[scopeKey] = order;
+    }
+  }
+  return relevantOrderByScope;
+}
+
+export function useWorkspaceStructure(serverId: string | null): WorkspaceStructure {
+  const projects = useStoreWithEqualityFn(
+    useSessionStore,
+    (state) => selectWorkspaceStructureProjects(state, serverId),
+    equal,
+  );
+  const projectOrder = useStoreWithEqualityFn(
+    useSidebarOrderStore,
+    (state) =>
+      serverId
+        ? (state.projectOrderByServerId[serverId] ?? EMPTY_WORKSPACE_KEYS)
+        : EMPTY_WORKSPACE_KEYS,
+    equal,
+  );
+  const workspaceOrderByScope = useStoreWithEqualityFn(
+    useSidebarOrderStore,
+    (state) =>
+      selectWorkspaceOrderByScopeForServer(state.workspaceOrderByServerAndProject, serverId),
+    equal,
+  );
+
+  return useMemo(() => {
+    if (!serverId || projects.length === 0) {
+      return EMPTY_WORKSPACE_STRUCTURE;
+    }
+
+    const orderedProjects = applyStoredOrdering({
+      items: projects.map((project) => {
+        const workspaceOrder =
+          workspaceOrderByScope[getWorkspaceOrderScopeKey(serverId, project.projectKey)] ??
+          EMPTY_WORKSPACE_KEYS;
+        const workspaceItems = project.workspaceKeys.map((workspaceId) => ({
+          workspaceId,
+          workspaceKey: `${serverId}:${workspaceId}`,
+        }));
+        return {
+          ...project,
+          workspaceKeys: applyStoredOrdering({
+            items: workspaceItems,
+            storedOrder: workspaceOrder,
+            getKey: (workspace) => workspace.workspaceKey,
+          }).map((workspace) => workspace.workspaceId),
+        };
+      }),
+      storedOrder: projectOrder,
+      getKey: (project) => project.projectKey,
+    });
+
+    return { projects: orderedProjects };
+  }, [projectOrder, projects, serverId, workspaceOrderByScope]);
+}
+
+export function useWorkspaceKeys(serverId: string | null): string[] {
+  return useStoreWithEqualityFn(
+    useSessionStore,
+    (state) => {
+      if (!serverId) {
+        return EMPTY_WORKSPACE_KEYS;
+      }
+      const workspaces = state.sessions[serverId]?.workspaces;
+      return workspaces ? Array.from(workspaces.keys()) : EMPTY_WORKSPACE_KEYS;
+    },
+    equal,
+  );
+}
+
+export function useRecommendedProjectPaths(serverId: string | null): string[] {
+  return useStoreWithEqualityFn(
+    useSessionStore,
+    (state) => {
+      if (!serverId) {
+        return EMPTY_WORKSPACE_KEYS;
+      }
+      const workspaces = state.sessions[serverId]?.workspaces;
+      if (!workspaces) {
+        return EMPTY_WORKSPACE_KEYS;
+      }
+      return Array.from(workspaces.values())
+        .map((workspace) => workspace.projectRootPath)
+        .filter((path) => path.length > 0);
+    },
+    equal,
+  );
+}
+
+export function useHasWorkspaces(serverId: string | null): boolean {
+  return useStoreWithEqualityFn(
+    useSessionStore,
+    (state) => {
+      if (!serverId) {
+        return false;
+      }
+      return (state.sessions[serverId]?.workspaces?.size ?? 0) > 0;
+    },
+    Object.is,
+  );
+}
+
+export function useResolveWorkspaceIdByCwd(
+  serverId: string | null,
+  cwd: string | null | undefined,
+): string | null {
+  return useStoreWithEqualityFn(
+    useSessionStore,
+    (state) => {
+      if (!serverId || !cwd) {
+        return null;
+      }
+      const workspaces = state.sessions[serverId]?.workspaces;
+      return resolveWorkspaceIdByExecutionDirectory({
+        workspaces: workspaces?.values(),
+        workspaceDirectory: cwd,
+      });
+    },
+    Object.is,
+  );
+}
+
+export function useWorkspaceStatusesForBadges(): DesktopBadgeWorkspaceStatus[] {
+  return useStoreWithEqualityFn(
+    useSessionStore,
+    (state) => {
+      const statuses: DesktopBadgeWorkspaceStatus[] = [];
+      for (const session of Object.values(state.sessions)) {
+        for (const workspace of session.workspaces.values()) {
+          statuses.push(workspace.status);
+        }
+      }
+      return statuses;
+    },
+    equal,
+  );
+}
--- a/packages/app/src/stores/session-store.test.ts
+++ b/packages/app/src/stores/session-store.test.ts
@@ -9,6 +9,7 @@ import {
  useSessionStore,
  type WorkspaceDescriptor,
 } from "./session-store";
+import { patchWorkspaceScripts } from "../contexts/session-workspace-scripts";

 function createWorkspace(
  input: Partial<WorkspaceDescriptor> & Pick<WorkspaceDescriptor, "id">,
@@ -32,6 +33,23 @@ afterEach(() => {
  useSessionStore.getState().clearSession("test-server");
 });

+function initializeTestSession(): void {
+  useSessionStore.getState().initializeSession("test-server", null as unknown as DaemonClient);
+}
+
+function getTestSessionReferences() {
+  const state = useSessionStore.getState();
+  const session = state.sessions["test-server"];
+  if (!session) {
+    throw new Error("test session is not initialized");
+  }
+  return {
+    sessions: state.sessions,
+    session,
+    workspaces: session.workspaces,
+  };
+}
+
 describe("normalizeWorkspaceDescriptor", () => {
  it("normalizes workspace scripts and invalid activity timestamps", () => {
    const scripts = [
@@ -138,6 +156,126 @@ describe("mergeWorkspaces", () => {
      },
    ]);
  });
+
+  it("preserves identity when merging content-equal workspace descriptors", () => {
+    const store = useSessionStore.getState();
+    initializeTestSession();
+    const workspace = createWorkspace({ id: "/repo/main" });
+
+    store.mergeWorkspaces("test-server", [workspace]);
+    const first = getTestSessionReferences();
+
+    store.mergeWorkspaces("test-server", [{ ...workspace, scripts: [...workspace.scripts] }]);
+    const second = getTestSessionReferences();
+
+    expect(second.sessions).toBe(first.sessions);
+    expect(second.session).toBe(first.session);
+    expect(second.workspaces).toBe(first.workspaces);
+    expect(second.workspaces.get("/repo/main")).toBe(first.workspaces.get("/repo/main"));
+  });
+
+  it("preserves unaffected workspace entry identity when one workspace changes", () => {
+    const store = useSessionStore.getState();
+    initializeTestSession();
+    const workspaceA = createWorkspace({ id: "/repo/a", name: "main" });
+    const workspaceB = createWorkspace({ id: "/repo/b", name: "feature" });
+
+    store.mergeWorkspaces("test-server", [workspaceA, workspaceB]);
+    const before = getTestSessionReferences();
+    const beforeA = before.workspaces.get("/repo/a");
+    const beforeB = before.workspaces.get("/repo/b");
+
+    store.mergeWorkspaces("test-server", [{ ...workspaceA, status: "running" }]);
+    const after = getTestSessionReferences();
+
+    expect(after.sessions).not.toBe(before.sessions);
+    expect(after.session).not.toBe(before.session);
+    expect(after.workspaces).not.toBe(before.workspaces);
+    expect(after.workspaces.get("/repo/a")).not.toBe(beforeA);
+    expect(after.workspaces.get("/repo/b")).toBe(beforeB);
+  });
+});
+
+describe("setWorkspaces", () => {
+  it("preserves identity when replacing workspaces with content-equal entries", () => {
+    const store = useSessionStore.getState();
+    initializeTestSession();
+    const workspace = createWorkspace({ id: "/repo/main" });
+    store.setWorkspaces("test-server", new Map([[workspace.id, workspace]]));
+    const before = getTestSessionReferences();
+
+    store.setWorkspaces(
+      "test-server",
+      new Map([[workspace.id, { ...workspace, scripts: [...workspace.scripts] }]]),
+    );
+    const after = getTestSessionReferences();
+
+    expect(after.sessions).toBe(before.sessions);
+    expect(after.session).toBe(before.session);
+    expect(after.workspaces).toBe(before.workspaces);
+    expect(after.workspaces.get(workspace.id)).toBe(before.workspaces.get(workspace.id));
+  });
+
+  it("stores replacement descriptors as-is when diff stat is cleared", () => {
+    const store = useSessionStore.getState();
+    initializeTestSession();
+    const workspace = createWorkspace({
+      id: "/repo/main",
+      diffStat: { additions: 2, deletions: 1 },
+    });
+    store.setWorkspaces("test-server", new Map([[workspace.id, workspace]]));
+    const before = getTestSessionReferences();
+
+    store.setWorkspaces("test-server", new Map([[workspace.id, { ...workspace, diffStat: null }]]));
+    const after = getTestSessionReferences();
+
+    expect(after.sessions).not.toBe(before.sessions);
+    expect(after.session).not.toBe(before.session);
+    expect(after.workspaces).not.toBe(before.workspaces);
+    expect(after.workspaces.get(workspace.id)?.diffStat).toBeNull();
+  });
+});
+
+describe("removeWorkspace", () => {
+  it("preserves identity when removing a missing workspace", () => {
+    const store = useSessionStore.getState();
+    initializeTestSession();
+    const workspace = createWorkspace({ id: "/repo/main" });
+    store.setWorkspaces("test-server", new Map([[workspace.id, workspace]]));
+    const before = getTestSessionReferences();
+
+    store.removeWorkspace("test-server", "/repo/missing");
+    const after = getTestSessionReferences();
+
+    expect(after.sessions).toBe(before.sessions);
+    expect(after.session).toBe(before.session);
+    expect(after.workspaces).toBe(before.workspaces);
+  });
+});
+
+describe("patchWorkspaceScripts", () => {
+  it("preserves workspace entry identity when scripts are content-equal", () => {
+    const script = {
+      scriptName: "web",
+      type: "service" as const,
+      hostname: "web.paseo.localhost",
+      port: 3000,
+      proxyUrl: "http://web.paseo.localhost:6767",
+      lifecycle: "running" as const,
+      health: "healthy" as const,
+      exitCode: null,
+    };
+    const workspace = createWorkspace({ id: "/repo/main", scripts: [script] });
+    const current = new Map([[workspace.id, workspace]]);
+
+    const next = patchWorkspaceScripts(current, {
+      workspaceId: workspace.id,
+      scripts: [{ ...script }],
+    });
+
+    expect(next).toBe(current);
+    expect(next.get(workspace.id)).toBe(workspace);
+  });
 });

 describe("mergeWorkspaceSnapshotWithExisting", () => {
--- a/packages/app/src/stores/session-store.ts
+++ b/packages/app/src/stores/session-store.ts
@@ -1,3 +1,4 @@
+import equal from "fast-deep-equal";
 import { create } from "zustand";
 import { subscribeWithSelector } from "zustand/middleware";
 import type { DaemonClient } from "@server/client/daemon-client";
@@ -159,6 +160,41 @@ export function mergeWorkspaceSnapshotWithExisting(input: {
  };
 }

+function preserveWorkspaceDescriptorIdentity(
+  incoming: WorkspaceDescriptor,
+  existing?: WorkspaceDescriptor | null,
+): WorkspaceDescriptor {
+  if (existing && equal(existing, incoming)) {
+    return existing;
+  }
+  return incoming;
+}
+
+function preserveWorkspaceMapIdentity(
+  existing: Map<string, WorkspaceDescriptor>,
+  incoming: Map<string, WorkspaceDescriptor>,
+): Map<string, WorkspaceDescriptor> {
+  if (existing === incoming) {
+    return existing;
+  }
+
+  const next = new Map<string, WorkspaceDescriptor>();
+  let changed = existing.size !== incoming.size;
+  const existingEntries = existing.entries();
+
+  for (const [key, workspace] of incoming) {
+    const existingWorkspace = existing.get(key);
+    const nextWorkspace = preserveWorkspaceDescriptorIdentity(workspace, existingWorkspace);
+    next.set(key, nextWorkspace);
+    const existingEntry = existingEntries.next().value;
+    if (!existingEntry || existingEntry[0] !== key || existingEntry[1] !== nextWorkspace) {
+      changed = true;
+    }
+  }
+
+  return changed ? next : existing;
+}
+
 export type ExplorerEntryKind = "file" | "directory";
 export type ExplorerFileKind = "text" | "image" | "binary";
 export type ExplorerEncoding = "utf-8" | "base64" | "none";
@@ -938,14 +974,18 @@ export const useSessionStore = create<SessionStore>()(
          }
          const nextWorkspaces =
            typeof workspaces === "function" ? workspaces(session.workspaces) : workspaces;
-          if (session.workspaces === nextWorkspaces) {
+          const preservedWorkspaces = preserveWorkspaceMapIdentity(
+            session.workspaces,
+            nextWorkspaces,
+          );
+          if (session.workspaces === preservedWorkspaces) {
            return prev;
          }
          return {
            ...prev,
            sessions: {
              ...prev.sessions,
-              [serverId]: { ...session, workspaces: nextWorkspaces },
+              [serverId]: { ...session, workspaces: preservedWorkspaces },
            },
          };
        });
@@ -962,13 +1002,15 @@ export const useSessionStore = create<SessionStore>()(
          let changed = false;
          for (const workspace of nextEntries) {
            const existing = next.get(workspace.id);
-            if (existing === workspace) {
+            const mergedWorkspace = mergeWorkspaceSnapshotWithExisting({
+              incoming: workspace,
+              existing,
+            });
+            const nextWorkspace = preserveWorkspaceDescriptorIdentity(mergedWorkspace, existing);
+            if (existing === nextWorkspace) {
              continue;
            }
-            next.set(
-              workspace.id,
-              mergeWorkspaceSnapshotWithExisting({ incoming: workspace, existing }),
-            );
+            next.set(workspace.id, nextWorkspace);
            changed = true;
          }
          if (!changed) {
--- a/packages/app/src/utils/sidebar-project-row-model.test.ts
+++ b/packages/app/src/utils/sidebar-project-row-model.test.ts
@@ -31,9 +31,6 @@ function project(overrides: Partial<SidebarProjectEntry> = {}): SidebarProjectEn
    projectName: "paseo",
    projectKind: "git",
    iconWorkingDir: "/repo",
-    statusBucket: "done",
-    activeCount: 0,
-    totalWorkspaces: 1,
    workspaces: [workspace()],
    ...overrides,
  };
--- a/packages/app/src/utils/sidebar-shortcuts.test.ts
+++ b/packages/app/src/utils/sidebar-shortcuts.test.ts
@@ -33,9 +33,6 @@ function project(projectKey: string, workspaces: SidebarWorkspaceEntry[]): Sideb
    projectName: projectKey,
    projectKind: "git",
    iconWorkingDir: workspaces[0]?.workspaceDirectory ?? "",
-    statusBucket: "done",
-    activeCount: 0,
-    totalWorkspaces: workspaces.length,
    workspaces,
  };
 }
--- a/packages/app/src/utils/workspace-fetch-debug.ts
+++ b/packages/app/src/utils/workspace-fetch-debug.ts
@@ -1,104 +0,0 @@
-type WorkspaceLike = {
-  id: string;
-  projectId: string;
-  projectDisplayName?: string;
-  name: string;
-  status: string;
-  workspaceKind: string;
-};
-
-type SidebarWorkspaceLike = {
-  workspaceId: string;
-  name: string;
-  statusBucket: string;
-  workspaceKind: string;
-};
-
-type SidebarProjectLike = {
-  projectKey: string;
-  projectName: string;
-  statusBucket: string;
-  activeCount: number;
-  totalWorkspaces: number;
-  workspaces: SidebarWorkspaceLike[];
-};
-
-function countByValue(values: Iterable<string>): Record<string, number> {
-  const counts = new Map<string, number>();
-  for (const value of values) {
-    counts.set(value, (counts.get(value) ?? 0) + 1);
-  }
-  return Object.fromEntries(counts);
-}
-
-export function summarizeWorkspaceCollection(
-  workspaces: Iterable<WorkspaceLike> | null | undefined,
-): {
-  count: number;
-  projectIds: string[];
-  statusCounts: Record<string, number>;
-  workspaces: Array<{
-    id: string;
-    projectId: string;
-    projectDisplayName: string | null;
-    name: string;
-    status: string;
-    workspaceKind: string;
-  }>;
-} {
-  const entries = Array.from(workspaces ?? [], (workspace) => ({
-    id: workspace.id,
-    projectId: workspace.projectId,
-    projectDisplayName: workspace.projectDisplayName?.trim() || null,
-    name: workspace.name,
-    status: workspace.status,
-    workspaceKind: workspace.workspaceKind,
-  }));
-
-  return {
-    count: entries.length,
-    projectIds: [...new Set(entries.map((workspace) => workspace.projectId))],
-    statusCounts: countByValue(entries.map((workspace) => workspace.status)),
-    workspaces: entries,
-  };
-}
-
-export function summarizeSidebarProjects(
-  projects: Iterable<SidebarProjectLike> | null | undefined,
-): {
-  count: number;
-  projectKeys: string[];
-  projects: Array<{
-    projectKey: string;
-    projectName: string;
-    statusBucket: string;
-    activeCount: number;
-    totalWorkspaces: number;
-    workspaces: Array<{
-      workspaceId: string;
-      name: string;
-      statusBucket: string;
-      workspaceKind: string;
-    }>;
-  }>;
-} {
-  const entries = Array.from(projects ?? [], (project) => ({
-    projectKey: project.projectKey,
-    projectName: project.projectName,
-    statusBucket: project.statusBucket,
-    activeCount: project.activeCount,
-    totalWorkspaces: project.totalWorkspaces,
-    workspaces: project.workspaces.map((workspace) => ({
-      workspaceId: workspace.workspaceId,
-      name: workspace.name,
-      statusBucket: workspace.statusBucket,
-      workspaceKind: workspace.workspaceKind,
-    })),
-  }));
-
-  return {
-    count: entries.length,
-    projectKeys: entries.map((project) => project.projectKey),
-    projects: entries,
-  };
-}