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_de.dart

@@ -2595,6 +2595,15 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get searchGroupPages => 'Seiten';
 
+  @override
+  String get searchGroupWorkspace => 'Projekte & Bereiche';
+
+  @override
+  String get searchWorkspaceHint => 'Kontext wechseln · ⌘P';
+
+  @override
+  String get searchWorkspaceSealedPickerHint => 'Auswahl öffnen · ⌘P';
+
   @override
   String get searchGroupModules => 'Module';
 
@@ -3414,7 +3423,30 @@ class AppLocalizationsDe extends AppLocalizations {
 
   @override
   String get workspaceSwitcherTooltip =>
-      'Arbeitsbereich — filtert diese Ansicht und stempelt neue Läufe mit dem gewählten Projekt';
+      'Arbeitskontext wählen — gilt überall: filtert Flows, Läufe, Audit und Freigaben und stempelt neue Läufe mit dem gewählten Projekt';
+
+  @override
+  String get workspaceAnchorCaption => 'Projekt / Bereich';
+
+  @override
+  String workspaceStartConfirmTitle(String name) {
+    return 'Bereich „$name“ starten?';
+  }
+
+  @override
+  String get workspaceStartConfirmBody =>
+      'Dieser abgeschottete Bereich ist gerade gestoppt. Studio startet seine eigene Hub-Instanz auf diesem Rechner und verbindet sich mit ihr — laufende Bereiche wechseln ohne diese Rückfrage.';
+
+  @override
+  String get workspaceStartConfirmAction => 'Starten und verbinden';
+
+  @override
+  String get workspaceSealedAggregateWhy =>
+      'Namen bleiben zusammengefasst, weil sie Mandanten verraten können.';
+
+  @override
+  String get workspaceSealedAggregateSettings =>
+      'Immer anzeigen: Einstellungen → Sicherheit';
 
   @override
   String get workspaceProtectedHint =>
@@ -3440,6 +3472,18 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get runsEmptyGuideButton => 'Anleitung öffnen';
 
+  @override
+  String runsEmptyFilteredTitle(String name) {
+    return 'Keine Läufe in Projekt „$name“';
+  }
+
+  @override
+  String get runsEmptyFilteredHint =>
+      'Der Arbeitskontext filtert diese Liste — in anderen Projekten kann es Läufe geben.';
+
+  @override
+  String get runsEmptyShowAll => 'Alle Projekte anzeigen';
+
   @override
   String get runsHubTooOldTitle =>
       'Diese Ansicht braucht eine neuere Hub-Version';