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/hooks/use-command-center.ts

@@ -4,14 +4,13 @@ import { router, usePathname, type Href } from "expo-router";
 import { useTranslation } from "react-i18next";
 import { useKeyboardShortcutsStore } from "@/stores/keyboard-shortcuts-store";
 import { keyboardActionDispatcher } from "@/keyboard/keyboard-action-dispatcher";
-import { useAllAgentsList } from "@/hooks/use-all-agents-list";
-import type { AggregatedAgent } from "@/hooks/use-aggregated-agents";
+import { useAggregatedAgents, type AggregatedAgent } from "@/hooks/use-aggregated-agents";
 import { useOpenProjectPicker } from "@/hooks/use-open-project-picker";
 import {
   clearCommandCenterFocusRestoreElement,
   takeCommandCenterFocusRestoreElement,
 } from "@/utils/command-center-focus-restore";
-import { buildHostOpenProjectRoute, buildSettingsRoute } from "@/utils/host-routes";
+import { buildOpenProjectRoute, buildSettingsRoute } from "@/utils/host-routes";
 import type { ShortcutKey } from "@/utils/format-shortcut";
 import { chordStringToShortcutKeys } from "@/keyboard/shortcut-string";
 import { getBindingIdForAction, getDefaultKeysForAction } from "@/keyboard/keyboard-shortcuts";
@@ -20,7 +19,6 @@ import { getShortcutOs } from "@/utils/shortcut-platform";
 import { getIsElectronRuntime } from "@/constants/layout";
 import { navigateToAgent } from "@/utils/navigate-to-agent";
 import { focusWithRetries } from "@/utils/web-focus";
-import { useActiveServerId } from "@/hooks/use-active-server-id";
 import { isWeb } from "@/constants/platform";
 
 const EMPTY_AGENTS: AggregatedAgent[] = [];
@@ -139,7 +137,6 @@ function resolveActionShortcutKeys(
 export function useCommandCenter() {
   const { t } = useTranslation();
   const pathname = usePathname();
-  const routeActiveServerId = useActiveServerId();
   const { overrides } = useKeyboardShortcutOverrides();
   const open = useKeyboardShortcutsStore((s) => s.commandCenterOpen);
   const setOpen = useKeyboardShortcutsStore((s) => s.setCommandCenterOpen);
@@ -153,11 +150,7 @@ export function useCommandCenter() {
   const [query, setQuery] = useState("");
   const [activeIndex, setActiveIndex] = useState(0);
 
-  const activeServerId = open ? routeActiveServerId : null;
-
-  const { agents } = useAllAgentsList({
-    serverId: activeServerId,
-  });
+  const { agents } = useAggregatedAgents();
 
   const agentResults = useMemo(() => {
     if (!open || agents.length === 0) {
@@ -172,10 +165,7 @@ export function useCommandCenter() {
     return buildSettingsRoute();
   }, []);
 
-  const homeRoute = useMemo<Href | undefined>(() => {
-    if (!routeActiveServerId) return undefined;
-    return buildHostOpenProjectRoute(routeActiveServerId) as Href;
-  }, [routeActiveServerId]);
+  const homeRoute = useMemo<Href>(() => buildOpenProjectRoute() as Href, []);
 
   const actionItems = useMemo(() => {
     if (!open) {
@@ -239,7 +229,7 @@ export function useCommandCenter() {
     [pathname, setOpen],
   );
 
-  const openProjectPicker = useOpenProjectPicker(activeServerId);
+  const openProjectPicker = useOpenProjectPicker();
 
   const handleSelectAction = useCallback(
     (action: CommandCenterActionItem) => {