Restore an archived workspace when its agent is reopened

Reopening an archived agent previously dead-ended at "workspace not
found": the agent record was un-archived but its workspace stayed
archived and was never sent to the client.

The daemon now un-archives the owning workspace alongside the agent when
its backing directory still exists, and the app auto-fires the restore
ahead of the missing-workspace gate so the user lands back in the
workspace rather than a dead end.

Worktrees whose directory was deleted on archive are not yet restorable
(recreating them from their branch is a follow-up); the workspace record
now persists its base branch as groundwork for that.

packages/app/src/i18n/resources/en.ts

@@ -327,6 +327,9 @@ export const en = {
   workspace: {
     route: {
       loading: "Loading workspace",
+      restoring: "Restoring workspace",
+      restoreFailed:
+        "Couldn't restore this workspace — the directory may have been moved or deleted",
       connecting: "Connecting",
       hostOffline: "{{hostName}} is offline",
       cannotReachHost: "Cannot reach {{hostName}}",