feat(workspace): one global switcher anchor in the shell sidebar

The switcher used to be embedded per page (Flows/Runs/Audit/
Approvals) — invisible on the other five pages and sitting in a
different corner depending on the page (persona review 2026-08-27,
consensus finding). It now lives ONCE in the sidebar, above the
destinations: active project/area always visible, opens the same
menu everywhere, Cmd+P from anywhere. The shell listens to the
workspace, so the sidebar endpoint label can no longer lag a
sealed switch until the next health tick.

Also in this rebuild:

* Stopped sealed areas ask before starting ("Start area X?") —
  a context switch must never boot a hub daemon as a click
  side-effect; running areas keep switching with one click.
* The switcher tooltip told a wrong scope ("filters this view") —
  it now says the choice applies everywhere and stamps new runs.
* The aggregated sealed row explains itself in place (names can
  reveal client identities) and links to the Settings toggle
  (Settings dialog gained an initialCategory jump).
* The active entry carries a checkmark in the menu.
* The Cmd+K palette knows projects and areas, ranked by recent
  use; sealed names honour the privacy setting — while hidden,
  the palette offers the guarded picker instead of the names.
* The runs empty state names the active project filter as the
  cause ("No runs in project X" + show-all action) instead of
  claiming the feature is off.

Tests updated to the anchor and made hermetic (scriptable
projects on the fake hub, sealed-area fake); new coverage for the
checkmark, the why-line, and the start confirmation.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/l10n/app_localizations_en.dart

@@ -2593,6 +2593,15 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get searchGroupPages => 'Pages';
 
+  @override
+  String get searchGroupWorkspace => 'Projects & areas';
+
+  @override
+  String get searchWorkspaceHint => 'switch context · ⌘P';
+
+  @override
+  String get searchWorkspaceSealedPickerHint => 'open the picker · ⌘P';
+
   @override
   String get searchGroupModules => 'Modules';
 
@@ -3407,7 +3416,30 @@ class AppLocalizationsEn extends AppLocalizations {
 
   @override
   String get workspaceSwitcherTooltip =>
-      'Workspace — filters this view and stamps new runs with the selected project';
+      'Choose the working context — applies everywhere: filters flows, runs, audit and approvals, and stamps new runs with the selected project';
+
+  @override
+  String get workspaceAnchorCaption => 'Project / area';
+
+  @override
+  String workspaceStartConfirmTitle(String name) {
+    return 'Start area “$name”?';
+  }
+
+  @override
+  String get workspaceStartConfirmBody =>
+      'This sealed area is currently stopped. Studio starts its own hub instance on this machine and connects to it — running areas switch without this prompt.';
+
+  @override
+  String get workspaceStartConfirmAction => 'Start and connect';
+
+  @override
+  String get workspaceSealedAggregateWhy =>
+      'Names stay aggregated because they can reveal client identities.';
+
+  @override
+  String get workspaceSealedAggregateSettings =>
+      'Always show: Settings → Security';
 
   @override
   String get workspaceProtectedHint =>
@@ -3433,6 +3465,18 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get runsEmptyGuideButton => 'Open the guide';
 
+  @override
+  String runsEmptyFilteredTitle(String name) {
+    return 'No runs in project “$name”';
+  }
+
+  @override
+  String get runsEmptyFilteredHint =>
+      'The working context filters this list — other projects may have runs.';
+
+  @override
+  String get runsEmptyShowAll => 'Show all projects';
+
   @override
   String get runsHubTooOldTitle => 'This view needs a newer hub version';