feat(settings): multi-version uninstall picker + default_scope editor

Two operator surfaces shipped together:

**Multi-version uninstall picker** — when more than one version
of a `(provider, name)` is installed side-by-side, both the
module-sheet "Uninstall" affordance and the store-detail
"Uninstall" affordance now ask the operator which version to
remove before calling the RPC. The hub's wire-level support for
this (UninstallModuleRequest.version) was already there; Studio
just wasn't using it. Picker pre-selects the highest version so
single-version flows still take one click.

  - `HubService.installedVersions(name)` enumerates the installed
    versions via the capabilities list.
  - `HubService.uninstallModule(name, version: ...)` forwards
    the version into the RPC.
  - `_UninstallVersionPickerDialog` (module sheet) and
    `_StoreUninstallVersionPickerDialog` (store) host the
    picker — separate widgets so each surface can evolve copy
    independently. Uses `RadioGroup<String>` for Flutter
    3.32+ deprecation compliance.

**Default scope editor** — new DEFAULT SCOPE panel in Settings
that calls the freshly-added HubAdmin RPCs
`GetDefaultScope` / `SetDefaultScope`. Operators can:

  - reorder publisher segments with up/down buttons
    (first match wins in the bare-form resolver),
  - delete entries (hub still rejects empty list — Studio
    surfaces the constraint inline),
  - add arbitrary entries via the text field,
  - add catalog-known publishers via suggestion chips
    (sorted alphabetically, populated from the catalog).

Every change persists to `~/.fai/config.yaml` via the hub
and hot-swaps the in-memory copy without a daemon restart.

Bumped pubspec to 0.48.0. dart analyze clean (No issues
found!); flutter test green (11 tests).

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

lib/l10n/app_de.arb

@@ -777,6 +777,25 @@
     }
   },
   "storeAdvisoryVersionTooltip": "Föderierter Upstream-Dienst — Version ist Richtwert; der Upstream kann ohne Versionsanhebung Kompatibilität brechen.",
+  "uninstallVersionPickerTitle": "Version zum Entfernen wählen",
+  "uninstallVersionPickerBody": "Mehrere Versionen von `{module}` sind parallel installiert. Wähle genau die Version aus, die entfernt werden soll — die anderen bleiben bestehen.",
+  "@uninstallVersionPickerBody": {
+    "placeholders": {
+      "module": {
+        "type": "String"
+      }
+    }
+  },
+  "uninstallVersionPickerContinue": "Weiter",
+  "defaultScopeHeader": "STANDARD-SCOPE",
+  "defaultScopeBlurb": "Geordnete Liste von Publisher-Segmenten, die der Hub konsultiert, wenn ein Flow eine Capability ohne explizites `<provider>/`-Präfix benennt. Erster Treffer gewinnt — die Segmente, die euer Team am häufigsten nutzt, gehören nach oben. Katalog-bekannte Publisher erscheinen als Chips; private Segmente lassen sich frei eintragen.",
+  "defaultScopeAddLabel": "Publisher-Segment hinzufügen",
+  "defaultScopeAddHint": "z.B. acme.team",
+  "defaultScopeAddButton": "Hinzufügen",
+  "defaultScopeSuggestions": "Katalog-Vorschläge:",
+  "defaultScopeSavedToast": "Standard-Scope aktualisiert.",
+  "defaultScopeLoadFailed": "Standard-Scope konnte nicht geladen werden.",
+  "defaultScopeNonEmptyError": "Standard-Scope darf nicht leer sein — mindestens ein Segment muss erhalten bleiben.",
   "maintenanceHeader": "HUB-WARTUNG",
   "maintenanceResetBlurb": "Operator-Zustand zurücksetzen und mit einem sauberen Hub neu starten. Stoppt jeden laufenden Daemon, sichert ~/.fai/ atomar in ein Backup, legt es dann neu an — Binary, Channel-Pointer, MCP-/n8n-/System-AI-Konfiguration und Registry-Token bleiben erhalten. Wiederherstellen durch Zurückverschieben des Backup-Ordners.",
   "maintenanceKeepModulesTitle": "Installierte Module behalten",

lib/l10n/app_en.arb

@@ -780,6 +780,25 @@
     }
   },
   "storeAdvisoryVersionTooltip": "Federated upstream service — version is advisory; the upstream may break compatibility without bumping it.",
+  "uninstallVersionPickerTitle": "Pick a version to uninstall",
+  "uninstallVersionPickerBody": "Several versions of `{module}` are installed side-by-side. Select the exact version to remove — the others stay in place.",
+  "@uninstallVersionPickerBody": {
+    "placeholders": {
+      "module": {
+        "type": "String"
+      }
+    }
+  },
+  "uninstallVersionPickerContinue": "Continue",
+  "defaultScopeHeader": "DEFAULT SCOPE",
+  "defaultScopeBlurb": "Ordered list of publisher segments the hub consults when a flow names a capability without an explicit `<provider>/` prefix. First match wins — promote the segments your team uses most to the top. Catalog-known publishers appear as chips; arbitrary entries are accepted for private segments.",
+  "defaultScopeAddLabel": "Add publisher segment",
+  "defaultScopeAddHint": "e.g. acme.team",
+  "defaultScopeAddButton": "Add",
+  "defaultScopeSuggestions": "Catalog suggestions:",
+  "defaultScopeSavedToast": "Default scope updated.",
+  "defaultScopeLoadFailed": "Could not load default scope.",
+  "defaultScopeNonEmptyError": "Default scope cannot be empty — keep at least one segment.",
   "maintenanceHeader": "HUB MAINTENANCE",
   "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.",
   "maintenanceKeepModulesTitle": "Keep installed modules",

lib/l10n/app_localizations.dart

@@ -2252,6 +2252,78 @@ abstract class AppLocalizations {
   /// **'Federated upstream service — version is advisory; the upstream may break compatibility without bumping it.'**
   String get storeAdvisoryVersionTooltip;
 
+  /// No description provided for @uninstallVersionPickerTitle.
+  ///
+  /// In en, this message translates to:
+  /// **'Pick a version to uninstall'**
+  String get uninstallVersionPickerTitle;
+
+  /// No description provided for @uninstallVersionPickerBody.
+  ///
+  /// In en, this message translates to:
+  /// **'Several versions of `{module}` are installed side-by-side. Select the exact version to remove — the others stay in place.'**
+  String uninstallVersionPickerBody(String module);
+
+  /// No description provided for @uninstallVersionPickerContinue.
+  ///
+  /// In en, this message translates to:
+  /// **'Continue'**
+  String get uninstallVersionPickerContinue;
+
+  /// No description provided for @defaultScopeHeader.
+  ///
+  /// In en, this message translates to:
+  /// **'DEFAULT SCOPE'**
+  String get defaultScopeHeader;
+
+  /// No description provided for @defaultScopeBlurb.
+  ///
+  /// In en, this message translates to:
+  /// **'Ordered list of publisher segments the hub consults when a flow names a capability without an explicit `<provider>/` prefix. First match wins — promote the segments your team uses most to the top. Catalog-known publishers appear as chips; arbitrary entries are accepted for private segments.'**
+  String get defaultScopeBlurb;
+
+  /// No description provided for @defaultScopeAddLabel.
+  ///
+  /// In en, this message translates to:
+  /// **'Add publisher segment'**
+  String get defaultScopeAddLabel;
+
+  /// No description provided for @defaultScopeAddHint.
+  ///
+  /// In en, this message translates to:
+  /// **'e.g. acme.team'**
+  String get defaultScopeAddHint;
+
+  /// No description provided for @defaultScopeAddButton.
+  ///
+  /// In en, this message translates to:
+  /// **'Add'**
+  String get defaultScopeAddButton;
+
+  /// No description provided for @defaultScopeSuggestions.
+  ///
+  /// In en, this message translates to:
+  /// **'Catalog suggestions:'**
+  String get defaultScopeSuggestions;
+
+  /// No description provided for @defaultScopeSavedToast.
+  ///
+  /// In en, this message translates to:
+  /// **'Default scope updated.'**
+  String get defaultScopeSavedToast;
+
+  /// No description provided for @defaultScopeLoadFailed.
+  ///
+  /// In en, this message translates to:
+  /// **'Could not load default scope.'**
+  String get defaultScopeLoadFailed;
+
+  /// No description provided for @defaultScopeNonEmptyError.
+  ///
+  /// In en, this message translates to:
+  /// **'Default scope cannot be empty — keep at least one segment.'**
+  String get defaultScopeNonEmptyError;
+
   /// No description provided for @maintenanceHeader.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_de.dart

@@ -1288,6 +1288,47 @@ class AppLocalizationsDe extends AppLocalizations {
   String get storeAdvisoryVersionTooltip =>
       'Föderierter Upstream-Dienst — Version ist Richtwert; der Upstream kann ohne Versionsanhebung Kompatibilität brechen.';
 
+  @override
+  String get uninstallVersionPickerTitle => 'Version zum Entfernen wählen';
+
+  @override
+  String uninstallVersionPickerBody(String module) {
+    return 'Mehrere Versionen von `$module` sind parallel installiert. Wähle genau die Version aus, die entfernt werden soll — die anderen bleiben bestehen.';
+  }
+
+  @override
+  String get uninstallVersionPickerContinue => 'Weiter';
+
+  @override
+  String get defaultScopeHeader => 'STANDARD-SCOPE';
+
+  @override
+  String get defaultScopeBlurb =>
+      'Geordnete Liste von Publisher-Segmenten, die der Hub konsultiert, wenn ein Flow eine Capability ohne explizites `<provider>/`-Präfix benennt. Erster Treffer gewinnt — die Segmente, die euer Team am häufigsten nutzt, gehören nach oben. Katalog-bekannte Publisher erscheinen als Chips; private Segmente lassen sich frei eintragen.';
+
+  @override
+  String get defaultScopeAddLabel => 'Publisher-Segment hinzufügen';
+
+  @override
+  String get defaultScopeAddHint => 'z.B. acme.team';
+
+  @override
+  String get defaultScopeAddButton => 'Hinzufügen';
+
+  @override
+  String get defaultScopeSuggestions => 'Katalog-Vorschläge:';
+
+  @override
+  String get defaultScopeSavedToast => 'Standard-Scope aktualisiert.';
+
+  @override
+  String get defaultScopeLoadFailed =>
+      'Standard-Scope konnte nicht geladen werden.';
+
+  @override
+  String get defaultScopeNonEmptyError =>
+      'Standard-Scope darf nicht leer sein — mindestens ein Segment muss erhalten bleiben.';
+
   @override
   String get maintenanceHeader => 'HUB-WARTUNG';
 

lib/l10n/app_localizations_en.dart

@@ -1303,6 +1303,46 @@ class AppLocalizationsEn extends AppLocalizations {
   String get storeAdvisoryVersionTooltip =>
       'Federated upstream service — version is advisory; the upstream may break compatibility without bumping it.';
 
+  @override
+  String get uninstallVersionPickerTitle => 'Pick a version to uninstall';
+
+  @override
+  String uninstallVersionPickerBody(String module) {
+    return 'Several versions of `$module` are installed side-by-side. Select the exact version to remove — the others stay in place.';
+  }
+
+  @override
+  String get uninstallVersionPickerContinue => 'Continue';
+
+  @override
+  String get defaultScopeHeader => 'DEFAULT SCOPE';
+
+  @override
+  String get defaultScopeBlurb =>
+      'Ordered list of publisher segments the hub consults when a flow names a capability without an explicit `<provider>/` prefix. First match wins — promote the segments your team uses most to the top. Catalog-known publishers appear as chips; arbitrary entries are accepted for private segments.';
+
+  @override
+  String get defaultScopeAddLabel => 'Add publisher segment';
+
+  @override
+  String get defaultScopeAddHint => 'e.g. acme.team';
+
+  @override
+  String get defaultScopeAddButton => 'Add';
+
+  @override
+  String get defaultScopeSuggestions => 'Catalog suggestions:';
+
+  @override
+  String get defaultScopeSavedToast => 'Default scope updated.';
+
+  @override
+  String get defaultScopeLoadFailed => 'Could not load default scope.';
+
+  @override
+  String get defaultScopeNonEmptyError =>
+      'Default scope cannot be empty — keep at least one segment.';
+
   @override
   String get maintenanceHeader => 'HUB MAINTENANCE';