Merge sidebar workspaces across all connected hosts (#1538)

* Merge workspaces across all hosts in the sidebar

Replace per-host sidebar sections with a single merged project list.
Projects that exist on multiple hosts (matched by projectKey) are
collapsed into one row. Host identity is surfaced via:

- A status-only footer pill showing online/offline host counts
- Hover cards with a mandatory host row on every workspace entry
- Subtitles showing the host name when a project spans >1 host
- A host filter in the grouping dropdown (not a sidebar switcher)

Order and group-mode stores migrated from per-server to global keys
with zustand persist migrations. New-workspace screen now shows a
merged project list with a host selector combobox.

Key files:
- workspace-structure.ts: merge algorithm by projectKey
- sidebar-view-store.ts / sidebar-order-store.ts: global state
- sidebar-workspace-list.tsx: context-based subtitle injection
- new-workspace-screen.tsx: host selector in footer row

* Add host filtering to the merged sidebar

The sidebar now merges workspaces from every connected host, so a single
global "active host" no longer fits. Host selection becomes explicit per
action via a host chooser, and agent history pages across all hosts at
once. Removes the active-host / active-server-id model and the
all-agents-list hook that fed it.

* Fix rebase fallout: translate archive host error, update stale workspace-key test

archiveWorkspacesOptimistically used a raw "Host is not connected" string
that the i18n completeness test forbids; route it through i18n.t with the
existing hostDisconnected key. The selectors memoization test asserted
un-prefixed workspace keys, but merged-sidebar keys are serverId-prefixed.

* Fix sidebar review fallout

* Address sidebar review followups

* Fix sidebar workspace identity migration

* Address sidebar review followups

* Handle partial host history failures

* Fix merged sidebar project removal and E2E drift

* Restore history routes and project removal shape

* Remove sidebar host context plumbing

* Tighten sidebar status and host filter state

* Keep new workspace project selection host-compatible

* Migrate sidebar view storage

* Streamline host selection flows

* Update all-host history on archive

* Fix empty project sidebar action

Code regression: the main merge dropped the empty-project New workspace child row while keeping the empty project persistence contract. Restore the row using the project host target so the sidebar stays aligned with the no-host-selection model.

* Fix Japanese shortcut translation key

Stale-base integration: main added the Japanese locale after this branch added cycleAgentMode to the English shortcut help map. Merging main exposed the missing ja key in CI typecheck and resources.test.

* Fix Playwright speech teardown race

packages/app/src/runtime/host-runtime.test.ts

@@ -1201,6 +1201,48 @@ describe("HostRuntimeController", () => {
 });
 
 describe("HostRuntimeStore", () => {
+  it("marks the host registry loaded after boot reads storage", async () => {
+    const previousOverride = process.env.EXPO_PUBLIC_LOCAL_DAEMON;
+    process.env.EXPO_PUBLIC_LOCAL_DAEMON = "not-an-endpoint";
+    const store = new HostRuntimeStore({
+      deps: {
+        createClient: () => {
+          throw new Error("createClient should not be called");
+        },
+        connectToDaemon: async () => {
+          throw new Error("connectToDaemon should not be called");
+        },
+        getClientId: async () => "cid_test_runtime",
+      },
+    });
+
+    try {
+      let hostListNotifications = 0;
+      let unsubscribeHostList = () => {};
+      const registryLoaded = new Promise<void>((resolve) => {
+        unsubscribeHostList = store.subscribeHostList(() => {
+          hostListNotifications += 1;
+          if (store.isHostRegistryLoaded()) {
+            unsubscribeHostList();
+            resolve();
+          }
+        });
+      });
+
+      store.boot();
+      await registryLoaded;
+
+      expect(store.isHostRegistryLoaded()).toBe(true);
+      expect(hostListNotifications).toBe(2);
+    } finally {
+      if (previousOverride === undefined) {
+        delete process.env.EXPO_PUBLIC_LOCAL_DAEMON;
+      } else {
+        process.env.EXPO_PUBLIC_LOCAL_DAEMON = previousOverride;
+      }
+    }
+  });
+
   it("bootstraps agent directory subscription when host transitions online", async () => {
     const host = makeHost({
       connections: [