fix(plugins): a host switch drops the branch and metadata even when the project id repeats

A remote repository keeps the same project id on every host, so comparing the project id alone
missed a switch from host A to host B for the same repository. The target is now the host and the
project id together.

packages/app/src/plugins/new-workspace-items/model.test.ts

@@ -39,6 +39,7 @@ describe("the base ref a plugin reads", () => {
     const chosen: PickerItem[] = [];
     const setup = createNewWorkspaceSetup(
       {
+        serverId: "host-a",
         locked: false,
         project: { id: "p", name: "repo" },
         canCreateWorktree: true,

packages/app/src/screens/new-workspace-screen.tsx

@@ -1654,7 +1654,7 @@ function usePluginSetup(input: {
     () => (projectId && projectName ? { id: projectId, name: projectName } : null),
     [projectId, projectName],
   );
-  const inputs = { locked, project: pluginProject, canCreateWorktree, supportsMetadata };
+  const inputs = { serverId, locked, project: pluginProject, canCreateWorktree, supportsMetadata };
   // Both are stable for the life of the screen: preferences write through the query client, and
   // the draft is keyed per mount. A command and a pick run the same effects.
   const [setup] = useState(() =>

packages/app/src/screens/new-workspace/setup-model.test.ts

@@ -3,6 +3,7 @@ import type { PickerItem } from "../new-workspace-picker-item";
 import { createNewWorkspaceSetup, type SetupEffects, type SetupInputs } from "./setup-model";
 
 const READY: SetupInputs = {
+  serverId: "host-a",
   locked: false,
   project: { id: "p1", name: "repo" },
   canCreateWorktree: true,
@@ -76,6 +77,17 @@ describe("New workspace setup commands", () => {
     expect(setup.getSnapshot().metadata).toEqual({});
   });
 
+  it("drops the branch and metadata when the host changes under the same project id", async () => {
+    const setup = createNewWorkspaceSetup(READY, recordingEffects().effects);
+    await setup.commands.setBranch("pas-101");
+    await setup.commands.setMetadata({ issue: "PAS-101" });
+
+    setup.syncInputs({ ...READY, serverId: "host-b" });
+
+    expect(setup.getSnapshot().branch).toBeNull();
+    expect(setup.getSnapshot().metadata).toEqual({});
+  });
+
   it("rejects every command while the screen is locked, as the pickers do", async () => {
     const setup = createNewWorkspaceSetup({ ...READY, locked: true }, recordingEffects().effects);
 

packages/app/src/screens/new-workspace/setup-model.ts

@@ -26,6 +26,8 @@ interface SetupState {
  * commit, so a command reads it at the moment it runs rather than from the render that built it.
  */
 export interface SetupInputs {
+  /** The host the screen creates on; a project id alone can repeat across hosts. */
+  serverId: string;
   locked: boolean;
   project: { id: string; name: string } | null;
   canCreateWorktree: boolean;
@@ -80,7 +82,7 @@ export function createNewWorkspaceSetup(
     metadata: {},
   };
   let inputs = initial;
-  let target = initial.project?.id ?? null;
+  let target = initial.project ? `${initial.serverId}\n${initial.project.id}` : null;
   const listeners = new Set<() => void>();
   const update = (patch: Partial<SetupState>) => {
     state = { ...state, ...patch };
@@ -111,12 +113,13 @@ export function createNewWorkspaceSetup(
     chooseIsolation,
     syncInputs: (next) => {
       inputs = next;
-      // A branch and metadata are chosen for one project on one host. A project id is
-      // host-scoped, so a change of host changes it too. An absent project is a screen that is
-      // still resolving, not a switch.
+      // A branch and metadata are chosen for one project on one host. A project id can repeat
+      // across hosts (a remote repository keeps its key everywhere), so the host is part of the
+      // target. An absent project is a screen that is still resolving, not a switch.
       if (!next.project) return;
-      if (target && target !== next.project.id) update({ branch: null, metadata: {} });
-      target = next.project.id;
+      const nextTarget = `${next.serverId}\n${next.project.id}`;
+      if (target && target !== nextTarget) update({ branch: null, metadata: {} });
+      target = nextTarget;
     },
     commands: {
       async setIsolation(isolation) {