fix(app): keep the sidebar alive when a workspace entry has not hydrated (#7896)

ProjectBlock asserted that every placement in a project has an entry in
workspaceEntriesByKey. A retained sidebar that is inactive (compact layout
with the sidebar closed) or still waiting for sessions keeps an empty map,
and Show background stops the project list from being pruned to hydrated
entries. From the eighth workspace on, selectSidebarGroupVisibility asked
for the status of a missing entry and the app crashed on start.

Count a missing entry as Done. It renders no row, so it should not claim a
slot past the limit.

Closes #7869

Co-authored-by: brucey0x <11062155+brucey0x@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

packages/app/src/components/sidebar-workspace-list.test.tsx

@@ -2,6 +2,7 @@
  * @vitest-environment jsdom
  */
 import { act, renderHook } from "@testing-library/react";
+import { createWorkspaceVisibilityPolicy } from "@/components/sidebar/sidebar-group-visibility";
 import { useLimitedSidebarGroup } from "@/components/sidebar/use-limited-sidebar-group";
 import type { DaemonClient } from "@getpaseo/client/internal/daemon-client";
 import type { WorkspaceScriptPayload } from "@getpaseo/protocol/messages";
@@ -486,6 +487,20 @@ describe("sidebar group visibility", () => {
     },
   );
 
+  it("treats placements without a hydrated entry as Done", () => {
+    const items = entries([...Array(8).fill("done"), "running", "done"]);
+    const hydrated = new Map(items.slice(0, 9).map((item) => [item.workspaceKey, item]));
+    for (const entriesByKey of [new Map(), hydrated]) {
+      const { result } = renderHook(() =>
+        useLimitedSidebarGroup(items, createWorkspaceVisibilityPolicy(entriesByKey)),
+      );
+      expect(result.current.canToggle).toBe(true);
+      expect(names(result.current.visibleItems)).toEqual(
+        entriesByKey.size === 0 ? names(items.slice(0, 7)) : [...names(items.slice(0, 7)), "row-9"],
+      );
+    }
+  });
+
   it("shows eight active rows once with no redundant toggle", () => {
     const items = entries([
       "running",

packages/app/src/components/sidebar-workspace-list.tsx

@@ -99,6 +99,7 @@ import {
 import { useLongPressDragInteraction } from "@/components/sidebar/use-long-press-drag-interaction";
 import { SidebarSectionHeader } from "@/components/sidebar/sidebar-section-header";
 import { SidebarGroupToggleRow } from "@/components/sidebar/sidebar-group-toggle-row";
+import { createWorkspaceVisibilityPolicy } from "@/components/sidebar/sidebar-group-visibility";
 import { useLimitedSidebarGroup } from "@/components/sidebar/use-limited-sidebar-group";
 import {
   SidebarWorkspaceRowFrame,
@@ -1593,11 +1594,7 @@ function ProjectBlock({
   onToggleWorkspacePin: ToggleSidebarWorkspacePin;
 }) {
   const visibilityPolicy = useMemo(
-    () => ({
-      kind: "workspaces" as const,
-      getStatusBucket: (workspace: SidebarWorkspacePlacement) =>
-        workspaceEntriesByKey.get(workspace.workspaceKey)!.statusBucket,
-    }),
+    () => createWorkspaceVisibilityPolicy<SidebarWorkspacePlacement>(workspaceEntriesByKey),
     [workspaceEntriesByKey],
   );
   const {

packages/app/src/components/sidebar/sidebar-group-visibility.ts

@@ -4,6 +4,18 @@ export type SidebarGroupVisibilityPolicy<T> =
   | { kind: "pinned" }
   | { kind: "workspaces"; getStatusBucket: (item: T) => SidebarStateBucket };
 
+// A placement can outrun its entry: a retained sidebar that is inactive (compact layout with the
+// sidebar closed) or still waiting for sessions keeps an empty entry map. A missing entry renders
+// no row, so it counts as Done and claims no slot past the limit.
+export function createWorkspaceVisibilityPolicy<T extends { workspaceKey: string }>(
+  entriesByKey: ReadonlyMap<string, { statusBucket: SidebarStateBucket }>,
+): SidebarGroupVisibilityPolicy<T> {
+  return {
+    kind: "workspaces",
+    getStatusBucket: (item) => entriesByKey.get(item.workspaceKey)?.statusBucket ?? "done",
+  };
+}
+
 export function selectSidebarGroupVisibility<T>(
   items: readonly T[],
   expanded: boolean,