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/utils/host-routes.ts

@@ -23,6 +23,11 @@ function extractSearch(pathname: string): string {
     : pathname.slice(queryIndex + 1);
 }
 
+function extractHash(pathname: string): string {
+  const hashIndex = pathname.indexOf("#");
+  return hashIndex >= 0 ? pathname.slice(hashIndex) : "";
+}
+
 function trimNonEmpty(value: NullableString): string | null {
   if (typeof value !== "string") {
     return null;
@@ -298,6 +303,38 @@ export function parseHostWorkspaceRouteFromPathname(
   return { serverId, workspaceId };
 }
 
+export function stripHostWorkspaceRouteEchoSearch(route: string): string {
+  const pathname = stripSearchAndHash(route);
+  const selection = parseHostWorkspaceRouteFromPathname(pathname);
+  const search = extractSearch(route);
+  if (!selection || !search) {
+    return route;
+  }
+
+  const params = new URLSearchParams(search);
+  let didStrip = false;
+
+  const serverId = params.get("serverId");
+  if (serverId && trimNonEmpty(decodeSegment(serverId)) === selection.serverId) {
+    params.delete("serverId");
+    didStrip = true;
+  }
+
+  const workspaceId = params.get("workspaceId");
+  if (workspaceId && decodeWorkspaceIdFromPathSegment(workspaceId) === selection.workspaceId) {
+    params.delete("workspaceId");
+    didStrip = true;
+  }
+
+  if (!didStrip) {
+    return route;
+  }
+
+  const nextSearch = params.toString();
+  const nextQuery = nextSearch ? `?${nextSearch}` : "";
+  return `${pathname}${nextQuery}${extractHash(route)}`;
+}
+
 export function buildHostWorkspaceRoute(serverId: string, workspaceId: string) {
   const normalizedServerId = trimNonEmpty(serverId);
   const normalizedWorkspaceId = trimNonEmpty(workspaceId);
@@ -353,6 +390,14 @@ export function buildHostRootRoute(serverId: string) {
   return `/h/${encodeSegment(normalized)}` as const;
 }
 
+export function buildHostOpenProjectRoute(serverId: string) {
+  const base = buildHostRootRoute(serverId);
+  if (base === "/") {
+    return "/" as const;
+  }
+  return `${base}/open-project` as const;
+}
+
 export function buildHostSessionsRoute(serverId: string) {
   const base = buildHostRootRoute(serverId);
   if (base === "/") {
@@ -361,12 +406,32 @@ export function buildHostSessionsRoute(serverId: string) {
   return `${base}/sessions` as const;
 }
 
-export function buildHostOpenProjectRoute(serverId: string) {
-  const base = buildHostRootRoute(serverId);
-  if (base === "/") {
-    return "/" as const;
+export function buildSessionsRoute() {
+  return "/sessions" as const;
+}
+
+export function buildOpenProjectRoute() {
+  return "/open-project" as const;
+}
+
+export type KnownHostRouteResolution =
+  | { kind: "render" }
+  | { kind: "redirect"; href: ReturnType<typeof buildOpenProjectRoute> | "/welcome" };
+
+export function resolveKnownHostRoute(input: {
+  routeServerId: string | null | undefined;
+  hosts: readonly { serverId: string }[];
+}): KnownHostRouteResolution {
+  const routeServerId = trimNonEmpty(input.routeServerId);
+  if (routeServerId && input.hosts.some((host) => host.serverId === routeServerId)) {
+    return { kind: "render" };
   }
-  return `${base}/open-project` as const;
+
+  if (input.hosts.length > 0) {
+    return { kind: "redirect", href: buildOpenProjectRoute() };
+  }
+
+  return { kind: "redirect", href: "/welcome" };
 }
 
 export function buildHostNewWorkspaceRoute(
@@ -448,6 +513,10 @@ export function buildSettingsSectionRoute(section: SettingsSectionSlug) {
   return `/settings/${section}` as const;
 }
 
+export function buildSettingsAddHostRoute(intentId: string | number = "1") {
+  return `/settings/general?addHost=${encodeURIComponent(String(intentId))}` as const;
+}
+
 export function buildSettingsHostRoute(serverId: string) {
   const normalized = trimNonEmpty(serverId);
   if (!normalized) {
@@ -475,30 +544,3 @@ export function buildProjectSettingsRoute(projectKey: string) {
   }
   return `/settings/projects/${encodeSegment(normalized)}` as const;
 }
-
-export function mapPathnameToServer(pathname: string, nextServerId: string) {
-  const normalized = trimNonEmpty(nextServerId);
-  if (!normalized) {
-    return "/" as const;
-  }
-
-  const suffix = pathname.replace(/^\/h\/[^/]+\/?/, "");
-  const base = buildHostRootRoute(normalized);
-  if (suffix.startsWith("settings")) {
-    return buildSettingsHostRoute(normalized);
-  }
-  if (suffix.startsWith("sessions")) {
-    return `${base}/sessions` as const;
-  }
-  if (suffix.startsWith("open-project")) {
-    return `${base}/open-project` as const;
-  }
-  const workspaceRoute = parseHostWorkspaceRouteFromPathname(pathname);
-  if (workspaceRoute) {
-    return buildHostWorkspaceRoute(normalized, workspaceRoute.workspaceId);
-  }
-  if (suffix.startsWith("agent/")) {
-    return `${base}/${suffix}` as const;
-  }
-  return base;
-}