feat(studio): clearer store + channel switcher + approvals & welcome polish

- store: repair the filter dialog crash (a Spacer lived directly in
  AlertDialog.actions, which is an OverflowBar, not a Flex — it threw
  and rendered a broken dialog). Buttons now sit in a Row.
- store: promote the module-store manager from a bare icon to a
  labelled 'Add store' button, and fully localize the dialog (DE/EN).
- store: add a curated 'Suggested stores' shelf with one-click
  add/remove (first entry: Recl∆Im). Each suggestion is probed for
  reachability and shows 'not available yet' until its index is
  published, instead of failing only on click. Fail-open on network
  errors so a transient hiccup never hides a real store.
- sidebar: the channel pill is now a one-click channel switcher
  (menu with per-channel running state + active check; switching
  writes ~/.chain/current-channel, restarts the daemon, and Studio
  repoints to the new channel).
- approvals: lead the card with the human prompt ('what am I
  releasing?') and demote the flow/step id to a metadata line; clear
  fallback when the step left the prompt empty.
- welcome: tidy the docs grid into equal-height paired rows with a
  full-width trailing card for the odd one out.

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

lib/l10n/app_de.arb

@@ -81,7 +81,7 @@
   "connectionStartHub": "Hub starten",
   "connectionTapToStart": "antippen zum Starten",
   "sidebarSettingsTooltip": "Einstellungen (⌘;)",
-  "sidebarChannelTooltip": "Aktiver Kanal — klicken um in Einstellungen (⌘;) zu wechseln.\nproduction = stabil · beta = Vorabversion · dev = laufend · local = Arbeitsumgebung",
+  "sidebarChannelTooltip": "Aktiver Kanal — klicken zum Wechseln.\nproduction = stabil · beta = Vorabversion · dev = laufend · local = Arbeitsumgebung",
   "buttonCancel": "Abbrechen",
   "buttonSave": "Speichern",
   "buttonClose": "Schließen",
@@ -319,6 +319,22 @@
     }
   },
   "storeReloadTooltip": "Aktualisieren",
+  "storesManagerButton": "Store hinzufügen",
+  "storesManagerTitle": "Module-Stores",
+  "storesManagerIntro": "Der Hub führt die Module aller Stores unten zu einem Index zusammen. Füge die Index-URL eines Stores hinzu, damit seine Module hier installierbar werden.",
+  "storesManagerAddSection": "Store hinzufügen",
+  "storesManagerNameLabel": "Name",
+  "storesManagerUrlLabel": "Index-URL (https:// oder file://)",
+  "storesManagerAddAction": "Hinzufügen",
+  "storesManagerBundled": "{count} Module · gebündelt",
+  "storesManagerModuleCount": "{count} Module",
+  "storesManagerAddFailed": "Store konnte nicht hinzugefügt werden",
+  "storesManagerRemoveFailed": "Store konnte nicht entfernt werden",
+  "storesManagerSuggested": "Vorgeschlagene Stores",
+  "storesManagerAddShort": "Hinzufügen",
+  "storesManagerNotAvailable": "Noch nicht verfügbar",
+  "storesManagerNotAvailableHint": "Der Anbieter hat diesen Store-Index noch nicht veröffentlicht. Sobald er das tut, ist er installierbar.",
+  "storesSuggestedReclaimDesc": "Recl∆Im — Module für Rechts- und Pflichten-Reform-Mapping",
   "storeTodayBadge": "HEUTE",
   "storeTodayDeck": "Von der Ch∆In-Redaktion",
   "storeTodayDismissTooltip": "Für diese Sitzung ausblenden",
@@ -998,7 +1014,9 @@
   "approvalsPillApproved": "freigegeben",
   "approvalsPillRejected": "abgelehnt",
   "approvalsPillExpired": "abgelaufen",
-  "approvalsPayloadPreview": "PAYLOAD-VORSCHAU",
+  "approvalsPayloadPreview": "DIESE DATEN WERDEN FREIGEGEBEN",
+  "approvalsRequestFallback": "Freigabe für diesen Schritt erforderlich",
+  "approvalsFlowStepMeta": "Flow: {flow} · Schritt: {step}",
   "approvalsApproveButton": "Freigeben",
   "approvalsRejectButton": "Ablehnen",
   "approvalsRejectDialogTitle": "Freigabe ablehnen",

lib/l10n/app_en.arb

@@ -84,7 +84,7 @@
   "connectionStartHub": "Start hub",
   "connectionTapToStart": "tap to start",
   "sidebarSettingsTooltip": "Settings (⌘;)",
-  "sidebarChannelTooltip": "Active channel — click to switch in Settings (⌘;).\nproduction = stable · beta = pre-release · dev = rolling · local = workspace",
+  "sidebarChannelTooltip": "Active channel — click to switch.\nproduction = stable · beta = pre-release · dev = rolling · local = workspace",
   "buttonCancel": "Cancel",
   "buttonSave": "Save",
   "buttonClose": "Close",
@@ -322,6 +322,32 @@
     }
   },
   "storeReloadTooltip": "Reload",
+  "storesManagerButton": "Add store",
+  "storesManagerTitle": "Module stores",
+  "storesManagerIntro": "The hub merges the modules from every store below into one index. Add a store's index URL to make its modules installable here.",
+  "storesManagerAddSection": "Add a store",
+  "storesManagerNameLabel": "Name",
+  "storesManagerUrlLabel": "Index URL (https:// or file://)",
+  "storesManagerAddAction": "Add store",
+  "storesManagerBundled": "{count} modules · bundled",
+  "@storesManagerBundled": {
+    "placeholders": {
+      "count": { "type": "int" }
+    }
+  },
+  "storesManagerModuleCount": "{count} modules",
+  "@storesManagerModuleCount": {
+    "placeholders": {
+      "count": { "type": "int" }
+    }
+  },
+  "storesManagerAddFailed": "Could not add store",
+  "storesManagerRemoveFailed": "Could not remove store",
+  "storesManagerSuggested": "Suggested stores",
+  "storesManagerAddShort": "Add",
+  "storesManagerNotAvailable": "Not available yet",
+  "storesManagerNotAvailableHint": "The provider hasn't published this store index yet. It will become installable once they do.",
+  "storesSuggestedReclaimDesc": "Recl∆Im — modules for law & duty reform-mapping",
   "storeTodayBadge": "TODAY",
   "storeTodayDeck": "From the Ch∆In editor",
   "storeTodayDismissTooltip": "Hide for this session",
@@ -1001,7 +1027,15 @@
   "approvalsPillApproved": "approved",
   "approvalsPillRejected": "rejected",
   "approvalsPillExpired": "expired",
-  "approvalsPayloadPreview": "PAYLOAD PREVIEW",
+  "approvalsPayloadPreview": "DATA TO BE RELEASED",
+  "approvalsRequestFallback": "Approval required for this step",
+  "approvalsFlowStepMeta": "Flow: {flow} · Step: {step}",
+  "@approvalsFlowStepMeta": {
+    "placeholders": {
+      "flow": { "type": "String" },
+      "step": { "type": "String" }
+    }
+  },
   "approvalsApproveButton": "Approve",
   "approvalsRejectButton": "Reject",
   "approvalsRejectDialogTitle": "Reject approval",

lib/l10n/app_localizations.dart

@@ -545,7 +545,7 @@ abstract class AppLocalizations {
   /// No description provided for @sidebarChannelTooltip.
   ///
   /// In en, this message translates to:
-  /// **'Active channel — click to switch in Settings (⌘;).\nproduction = stable · beta = pre-release · dev = rolling · local = workspace'**
+  /// **'Active channel — click to switch.\nproduction = stable · beta = pre-release · dev = rolling · local = workspace'**
   String get sidebarChannelTooltip;
 
   /// No description provided for @buttonCancel.
@@ -1436,6 +1436,102 @@ abstract class AppLocalizations {
   /// **'Reload'**
   String get storeReloadTooltip;
 
+  /// No description provided for @storesManagerButton.
+  ///
+  /// In en, this message translates to:
+  /// **'Add store'**
+  String get storesManagerButton;
+
+  /// No description provided for @storesManagerTitle.
+  ///
+  /// In en, this message translates to:
+  /// **'Module stores'**
+  String get storesManagerTitle;
+
+  /// No description provided for @storesManagerIntro.
+  ///
+  /// In en, this message translates to:
+  /// **'The hub merges the modules from every store below into one index. Add a store\'s index URL to make its modules installable here.'**
+  String get storesManagerIntro;
+
+  /// No description provided for @storesManagerAddSection.
+  ///
+  /// In en, this message translates to:
+  /// **'Add a store'**
+  String get storesManagerAddSection;
+
+  /// No description provided for @storesManagerNameLabel.
+  ///
+  /// In en, this message translates to:
+  /// **'Name'**
+  String get storesManagerNameLabel;
+
+  /// No description provided for @storesManagerUrlLabel.
+  ///
+  /// In en, this message translates to:
+  /// **'Index URL (https:// or file://)'**
+  String get storesManagerUrlLabel;
+
+  /// No description provided for @storesManagerAddAction.
+  ///
+  /// In en, this message translates to:
+  /// **'Add store'**
+  String get storesManagerAddAction;
+
+  /// No description provided for @storesManagerBundled.
+  ///
+  /// In en, this message translates to:
+  /// **'{count} modules · bundled'**
+  String storesManagerBundled(int count);
+
+  /// No description provided for @storesManagerModuleCount.
+  ///
+  /// In en, this message translates to:
+  /// **'{count} modules'**
+  String storesManagerModuleCount(int count);
+
+  /// No description provided for @storesManagerAddFailed.
+  ///
+  /// In en, this message translates to:
+  /// **'Could not add store'**
+  String get storesManagerAddFailed;
+
+  /// No description provided for @storesManagerRemoveFailed.
+  ///
+  /// In en, this message translates to:
+  /// **'Could not remove store'**
+  String get storesManagerRemoveFailed;
+
+  /// No description provided for @storesManagerSuggested.
+  ///
+  /// In en, this message translates to:
+  /// **'Suggested stores'**
+  String get storesManagerSuggested;
+
+  /// No description provided for @storesManagerAddShort.
+  ///
+  /// In en, this message translates to:
+  /// **'Add'**
+  String get storesManagerAddShort;
+
+  /// No description provided for @storesManagerNotAvailable.
+  ///
+  /// In en, this message translates to:
+  /// **'Not available yet'**
+  String get storesManagerNotAvailable;
+
+  /// No description provided for @storesManagerNotAvailableHint.
+  ///
+  /// In en, this message translates to:
+  /// **'The provider hasn\'t published this store index yet. It will become installable once they do.'**
+  String get storesManagerNotAvailableHint;
+
+  /// No description provided for @storesSuggestedReclaimDesc.
+  ///
+  /// In en, this message translates to:
+  /// **'Recl∆Im — modules for law & duty reform-mapping'**
+  String get storesSuggestedReclaimDesc;
+
   /// No description provided for @storeTodayBadge.
   ///
   /// In en, this message translates to:
@@ -2969,9 +3065,21 @@ abstract class AppLocalizations {
   /// No description provided for @approvalsPayloadPreview.
   ///
   /// In en, this message translates to:
-  /// **'PAYLOAD PREVIEW'**
+  /// **'DATA TO BE RELEASED'**
   String get approvalsPayloadPreview;
 
+  /// No description provided for @approvalsRequestFallback.
+  ///
+  /// In en, this message translates to:
+  /// **'Approval required for this step'**
+  String get approvalsRequestFallback;
+
+  /// No description provided for @approvalsFlowStepMeta.
+  ///
+  /// In en, this message translates to:
+  /// **'Flow: {flow} · Step: {step}'**
+  String approvalsFlowStepMeta(String flow, String step);
+
   /// No description provided for @approvalsApproveButton.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_de.dart

@@ -261,7 +261,7 @@ class AppLocalizationsDe extends AppLocalizations {
 
   @override
   String get sidebarChannelTooltip =>
-      'Aktiver Kanal — klicken um in Einstellungen (⌘;) zu wechseln.\nproduction = stabil · beta = Vorabversion · dev = laufend · local = Arbeitsumgebung';
+      'Aktiver Kanal — klicken zum Wechseln.\nproduction = stabil · beta = Vorabversion · dev = laufend · local = Arbeitsumgebung';
 
   @override
   String get buttonCancel => 'Abbrechen';
@@ -771,6 +771,61 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get storeReloadTooltip => 'Aktualisieren';
 
+  @override
+  String get storesManagerButton => 'Store hinzufügen';
+
+  @override
+  String get storesManagerTitle => 'Module-Stores';
+
+  @override
+  String get storesManagerIntro =>
+      'Der Hub führt die Module aller Stores unten zu einem Index zusammen. Füge die Index-URL eines Stores hinzu, damit seine Module hier installierbar werden.';
+
+  @override
+  String get storesManagerAddSection => 'Store hinzufügen';
+
+  @override
+  String get storesManagerNameLabel => 'Name';
+
+  @override
+  String get storesManagerUrlLabel => 'Index-URL (https:// oder file://)';
+
+  @override
+  String get storesManagerAddAction => 'Hinzufügen';
+
+  @override
+  String storesManagerBundled(int count) {
+    return '$count Module · gebündelt';
+  }
+
+  @override
+  String storesManagerModuleCount(int count) {
+    return '$count Module';
+  }
+
+  @override
+  String get storesManagerAddFailed => 'Store konnte nicht hinzugefügt werden';
+
+  @override
+  String get storesManagerRemoveFailed => 'Store konnte nicht entfernt werden';
+
+  @override
+  String get storesManagerSuggested => 'Vorgeschlagene Stores';
+
+  @override
+  String get storesManagerAddShort => 'Hinzufügen';
+
+  @override
+  String get storesManagerNotAvailable => 'Noch nicht verfügbar';
+
+  @override
+  String get storesManagerNotAvailableHint =>
+      'Der Anbieter hat diesen Store-Index noch nicht veröffentlicht. Sobald er das tut, ist er installierbar.';
+
+  @override
+  String get storesSuggestedReclaimDesc =>
+      'Recl∆Im — Module für Rechts- und Pflichten-Reform-Mapping';
+
   @override
   String get storeTodayBadge => 'HEUTE';
 
@@ -1712,7 +1767,16 @@ class AppLocalizationsDe extends AppLocalizations {
   String get approvalsPillExpired => 'abgelaufen';
 
   @override
-  String get approvalsPayloadPreview => 'PAYLOAD-VORSCHAU';
+  String get approvalsPayloadPreview => 'DIESE DATEN WERDEN FREIGEGEBEN';
+
+  @override
+  String get approvalsRequestFallback =>
+      'Freigabe für diesen Schritt erforderlich';
+
+  @override
+  String approvalsFlowStepMeta(String flow, String step) {
+    return 'Flow: $flow · Schritt: $step';
+  }
 
   @override
   String get approvalsApproveButton => 'Freigeben';

lib/l10n/app_localizations_en.dart

@@ -260,7 +260,7 @@ class AppLocalizationsEn extends AppLocalizations {
 
   @override
   String get sidebarChannelTooltip =>
-      'Active channel — click to switch in Settings (⌘;).\nproduction = stable · beta = pre-release · dev = rolling · local = workspace';
+      'Active channel — click to switch.\nproduction = stable · beta = pre-release · dev = rolling · local = workspace';
 
   @override
   String get buttonCancel => 'Cancel';
@@ -789,6 +789,61 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get storeReloadTooltip => 'Reload';
 
+  @override
+  String get storesManagerButton => 'Add store';
+
+  @override
+  String get storesManagerTitle => 'Module stores';
+
+  @override
+  String get storesManagerIntro =>
+      'The hub merges the modules from every store below into one index. Add a store\'s index URL to make its modules installable here.';
+
+  @override
+  String get storesManagerAddSection => 'Add a store';
+
+  @override
+  String get storesManagerNameLabel => 'Name';
+
+  @override
+  String get storesManagerUrlLabel => 'Index URL (https:// or file://)';
+
+  @override
+  String get storesManagerAddAction => 'Add store';
+
+  @override
+  String storesManagerBundled(int count) {
+    return '$count modules · bundled';
+  }
+
+  @override
+  String storesManagerModuleCount(int count) {
+    return '$count modules';
+  }
+
+  @override
+  String get storesManagerAddFailed => 'Could not add store';
+
+  @override
+  String get storesManagerRemoveFailed => 'Could not remove store';
+
+  @override
+  String get storesManagerSuggested => 'Suggested stores';
+
+  @override
+  String get storesManagerAddShort => 'Add';
+
+  @override
+  String get storesManagerNotAvailable => 'Not available yet';
+
+  @override
+  String get storesManagerNotAvailableHint =>
+      'The provider hasn\'t published this store index yet. It will become installable once they do.';
+
+  @override
+  String get storesSuggestedReclaimDesc =>
+      'Recl∆Im — modules for law & duty reform-mapping';
+
   @override
   String get storeTodayBadge => 'TODAY';
 
@@ -1722,7 +1777,15 @@ class AppLocalizationsEn extends AppLocalizations {
   String get approvalsPillExpired => 'expired';
 
   @override
-  String get approvalsPayloadPreview => 'PAYLOAD PREVIEW';
+  String get approvalsPayloadPreview => 'DATA TO BE RELEASED';
+
+  @override
+  String get approvalsRequestFallback => 'Approval required for this step';
+
+  @override
+  String approvalsFlowStepMeta(String flow, String step) {
+    return 'Flow: $flow · Step: $step';
+  }
 
   @override
   String get approvalsApproveButton => 'Approve';