feat(studio): hub maintenance panel with reset action (v0.45.0)

UI parity with the platform CLI: `fai reset` (v0.10.93) is now
reachable from Settings. The panel shows the reset blurb plus
two checkboxes mirroring the CLI flags (Keep modules / Keep
audit log + saved flows), then a destructive-styled "Reset hub
state" button. Click goes through a confirm dialog before
SystemActions.faiReset is invoked.

After the CLI returns, Studio bounces its gRPC channel against
the same endpoint (the daemon restarts on the same channel +
port, so no Settings change needed) and reloads every panel:
channel status, system AI, MCP clients, n8n endpoints, registry
token. Output (success or failure) is shown in a copyable error
box so any unexpected stderr lands somewhere the operator can
paste from.

Sits at the bottom of the dialog under "HUB MAINTENANCE",
separated from the everyday config so a destructive button
doesn't crowd the day-to-day controls.

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

lib/l10n/app_localizations_en.dart

@@ -1174,6 +1174,43 @@ class AppLocalizationsEn extends AppLocalizations {
     return 'Could not save: $error';
   }
 
+  @override
+  String get maintenanceHeader => 'HUB MAINTENANCE';
+
+  @override
+  String get maintenanceResetBlurb =>
+      'Wipe operator state and start over with a clean hub. Stops every running daemon, atomically backs ~/.fai/ up, then recreates it with the binary, channel state, MCP / n8n / system-AI config, and registry token preserved. Restore by moving the backup directory back.';
+
+  @override
+  String get maintenanceKeepModulesTitle => 'Keep installed modules';
+
+  @override
+  String get maintenanceKeepModulesSubtitle =>
+      'Default behaviour wipes ~/.fai/modules/ so a fresh install can verify the module-fetch path end-to-end.';
+
+  @override
+  String get maintenanceKeepDataTitle => 'Keep audit log + saved flows';
+
+  @override
+  String get maintenanceKeepDataSubtitle =>
+      'Default behaviour wipes ~/.fai/data/ so the audit chain restarts from a fresh genesis and the bundled sample flows re-import on first daemon start.';
+
+  @override
+  String get maintenanceResetButton => 'Reset hub state';
+
+  @override
+  String get maintenanceResetInProgress => 'Resetting…';
+
+  @override
+  String get maintenanceResetConfirmTitle => 'Reset hub state?';
+
+  @override
+  String get maintenanceResetConfirmBody =>
+      'This stops every daemon, moves ~/.fai/ to a timestamped backup, and starts fresh. The backup is fully restorable. Continue?';
+
+  @override
+  String get maintenanceResetConfirmButton => 'Reset';
+
   @override
   String get welcomeChecklistAllSetTitle => 'You\'re set up.';