feat(studio): plain-language store, bottom-anchored ask bar (v0.33.0)

The store had three structural problems flagged in user
feedback:

1. "Lernkurve zu hoch — alle bridge, debug, alpha, planned,
   keiner weiß was das heißt." Wire-level enum values bled
   through into the UI: `bridge`, `debug`, `published`,
   `alpha`, `planned`. Operators don't share the data model.

2. "Filter / Kategorien sollten oben in die Leiste neben Store
   zum ausklappen, der Body soll übersichtlicher werden." A
   chip-row plus category strip plus result-count line ate a
   full row of viewport on every screen.

3. "Suche passt besser an den unteren Bildschirmrand." The
   chat-style ask bar belongs at the bottom — Claude / ChatGPT
   / Slack pattern — not at the top where it competes with
   the Today hero.

Plus: "Es gibt noch ganz viele overflows in den Beschreibungen."

Changes:

- Plain-language display names. New ARB keys for category
  labels (Connectors / Sample modules / AI models / Storage /
  Channels / Authentication / Orchestration / …) and updated
  status values (stable / experimental / coming soon). Wire
  ids stay in StoreEntry, RPCs, seed.yaml — only the rendered
  pills and dropdowns get translated. Helpers
  `_categoryDisplayName` and `_statusDisplayName` keep the
  mapping in one place.

- Toolbar moves into the AppBar. The new `_CategoryDropdown`
  hosts the category picker as a popup-menu with localised
  labels; the existing `_FilterButton` lives next to it; the
  reload icon stays where it always was. The body no longer
  carries any chip strip or result-count line.

- Bottom-anchored `_AskBar`. The Scaffold body becomes a
  Column of `Expanded(scrollable content)` plus a pinned
  composer row at the foot of the viewport, with a top
  divider matching the chat-input pattern of modern AI
  assistants. AI answers now render at the top of the scroll
  (above the Today-Hero) so the operator sees them right
  after submitting the question at the bottom.

- Overflow sweep on descriptions. Today-Hero header row
  becomes a Wrap (badge + deck flow naturally on narrow
  windows), the title is bound to 3 lines, the body to 6.
  Card category text gets `maxLines: 1, ellipsis` in both
  StoreCard and FeaturedTile. Recommended-source card title
  gets the same treatment.

- Better toast for the "added but zero capabilities" path.
  When MCP discovery succeeds but returns no tools (typical
  Streamable-HTTP servers without Mcp-Session-Id support, or
  servers that need `notifications/initialized`), the toast
  now explains the situation in plain language and points
  the operator at Settings → MCP Clients to retry. Old
  pluralised toast still fires when N > 0.

Hub-side `notifications/initialized` for HTTP MCP and
Mcp-Session-Id support are out of scope for this commit;
tracked as a separate fai_hub follow-up.

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

lib/l10n/app_de.arb

@@ -127,10 +127,22 @@
   "storeNoMatchesHint": "Filter anpassen oder Suche leeren, um alle Einträge zu sehen.",
   "storeClearFilters": "Filter zurücksetzen",
   "storeStatusAll": "Alle",
-  "storeStatusPublished": "Veröffentlicht",
-  "storeStatusAlpha": "Alpha",
-  "storeStatusPlanned": "Geplant",
+  "storeStatusPublished": "stabil",
+  "storeStatusAlpha": "experimentell",
+  "storeStatusPlanned": "geplant",
   "storeInstalledOnly": "Installiert",
+  "storeCategoryLabel": "Kategorie",
+  "storeCategoryAll": "Alle Kategorien",
+  "storeCategoryBridge": "Verbindungen",
+  "storeCategoryDebug": "Beispiele",
+  "storeCategoryText": "Text",
+  "storeCategoryLlm": "KI-Modelle",
+  "storeCategorySystem": "System",
+  "storeCategoryAuth": "Authentifizierung",
+  "storeCategoryStorage": "Speicher",
+  "storeCategoryChannel": "Kanäle",
+  "storeCategoryWeb": "Web",
+  "storeCategoryOrchestrator": "Orchestrierung",
   "storeNResults": "{n} Treffer",
   "@storeNResults": {
     "placeholders": { "n": { "type": "int" } }
@@ -221,6 +233,10 @@
       "n": { "type": "int" }
     }
   },
+  "storeProviderAddedZeroToast": "{name} ist eingetragen, aber der Server hat noch keine Capabilities geliefert. Öffne Einstellungen → MCP-Clients, um Discovery erneut zu versuchen oder den Server zu prüfen.",
+  "@storeProviderAddedZeroToast": {
+    "placeholders": { "name": { "type": "String" } }
+  },
   "storeProviderAddFailed": "{name} konnte nicht hinzugefügt werden: {error}",
   "@storeProviderAddFailed": {
     "placeholders": {

lib/l10n/app_en.arb

@@ -128,10 +128,22 @@
   "storeNoMatchesHint": "Adjust the filters or clear the search to see all entries.",
   "storeClearFilters": "Clear filters",
   "storeStatusAll": "All",
-  "storeStatusPublished": "Published",
-  "storeStatusAlpha": "Alpha",
-  "storeStatusPlanned": "Planned",
+  "storeStatusPublished": "stable",
+  "storeStatusAlpha": "experimental",
+  "storeStatusPlanned": "coming soon",
   "storeInstalledOnly": "Installed",
+  "storeCategoryLabel": "Category",
+  "storeCategoryAll": "All categories",
+  "storeCategoryBridge": "Connectors",
+  "storeCategoryDebug": "Sample modules",
+  "storeCategoryText": "Text",
+  "storeCategoryLlm": "AI models",
+  "storeCategorySystem": "System",
+  "storeCategoryAuth": "Authentication",
+  "storeCategoryStorage": "Storage",
+  "storeCategoryChannel": "Channels",
+  "storeCategoryWeb": "Web",
+  "storeCategoryOrchestrator": "Orchestration",
   "storeNResults": "{n} result{n, plural, =1{} other{s}}",
   "@storeNResults": {
     "placeholders": { "n": { "type": "int" } }
@@ -222,6 +234,10 @@
       "n": { "type": "int" }
     }
   },
+  "storeProviderAddedZeroToast": "{name} registered, but the server returned no capabilities yet. Open Settings → MCP Clients to retry discovery or check the server.",
+  "@storeProviderAddedZeroToast": {
+    "placeholders": { "name": { "type": "String" } }
+  },
   "storeProviderAddFailed": "Could not add {name}: {error}",
   "@storeProviderAddFailed": {
     "placeholders": {

lib/l10n/app_localizations.dart

@@ -761,19 +761,19 @@ abstract class AppLocalizations {
   /// No description provided for @storeStatusPublished.
   ///
   /// In en, this message translates to:
-  /// **'Published'**
+  /// **'stable'**
   String get storeStatusPublished;
 
   /// No description provided for @storeStatusAlpha.
   ///
   /// In en, this message translates to:
-  /// **'Alpha'**
+  /// **'experimental'**
   String get storeStatusAlpha;
 
   /// No description provided for @storeStatusPlanned.
   ///
   /// In en, this message translates to:
-  /// **'Planned'**
+  /// **'coming soon'**
   String get storeStatusPlanned;
 
   /// No description provided for @storeInstalledOnly.
@@ -782,6 +782,78 @@ abstract class AppLocalizations {
   /// **'Installed'**
   String get storeInstalledOnly;
 
+  /// No description provided for @storeCategoryLabel.
+  ///
+  /// In en, this message translates to:
+  /// **'Category'**
+  String get storeCategoryLabel;
+
+  /// No description provided for @storeCategoryAll.
+  ///
+  /// In en, this message translates to:
+  /// **'All categories'**
+  String get storeCategoryAll;
+
+  /// No description provided for @storeCategoryBridge.
+  ///
+  /// In en, this message translates to:
+  /// **'Connectors'**
+  String get storeCategoryBridge;
+
+  /// No description provided for @storeCategoryDebug.
+  ///
+  /// In en, this message translates to:
+  /// **'Sample modules'**
+  String get storeCategoryDebug;
+
+  /// No description provided for @storeCategoryText.
+  ///
+  /// In en, this message translates to:
+  /// **'Text'**
+  String get storeCategoryText;
+
+  /// No description provided for @storeCategoryLlm.
+  ///
+  /// In en, this message translates to:
+  /// **'AI models'**
+  String get storeCategoryLlm;
+
+  /// No description provided for @storeCategorySystem.
+  ///
+  /// In en, this message translates to:
+  /// **'System'**
+  String get storeCategorySystem;
+
+  /// No description provided for @storeCategoryAuth.
+  ///
+  /// In en, this message translates to:
+  /// **'Authentication'**
+  String get storeCategoryAuth;
+
+  /// No description provided for @storeCategoryStorage.
+  ///
+  /// In en, this message translates to:
+  /// **'Storage'**
+  String get storeCategoryStorage;
+
+  /// No description provided for @storeCategoryChannel.
+  ///
+  /// In en, this message translates to:
+  /// **'Channels'**
+  String get storeCategoryChannel;
+
+  /// No description provided for @storeCategoryWeb.
+  ///
+  /// In en, this message translates to:
+  /// **'Web'**
+  String get storeCategoryWeb;
+
+  /// No description provided for @storeCategoryOrchestrator.
+  ///
+  /// In en, this message translates to:
+  /// **'Orchestration'**
+  String get storeCategoryOrchestrator;
+
   /// No description provided for @storeNResults.
   ///
   /// In en, this message translates to:
@@ -1100,6 +1172,12 @@ abstract class AppLocalizations {
   /// **'Added {name} — {n} federated {n, plural, =1{capability} other{capabilities}}.'**
   String storeProviderAddedToast(String name, int n);
 
+  /// No description provided for @storeProviderAddedZeroToast.
+  ///
+  /// In en, this message translates to:
+  /// **'{name} registered, but the server returned no capabilities yet. Open Settings → MCP Clients to retry discovery or check the server.'**
+  String storeProviderAddedZeroToast(String name);
+
   /// No description provided for @storeProviderAddFailed.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_de.dart

@@ -382,17 +382,53 @@ class AppLocalizationsDe extends AppLocalizations {
   String get storeStatusAll => 'Alle';
 
   @override
-  String get storeStatusPublished => 'Veröffentlicht';
+  String get storeStatusPublished => 'stabil';
 
   @override
-  String get storeStatusAlpha => 'Alpha';
+  String get storeStatusAlpha => 'experimentell';
 
   @override
-  String get storeStatusPlanned => 'Geplant';
+  String get storeStatusPlanned => 'geplant';
 
   @override
   String get storeInstalledOnly => 'Installiert';
 
+  @override
+  String get storeCategoryLabel => 'Kategorie';
+
+  @override
+  String get storeCategoryAll => 'Alle Kategorien';
+
+  @override
+  String get storeCategoryBridge => 'Verbindungen';
+
+  @override
+  String get storeCategoryDebug => 'Beispiele';
+
+  @override
+  String get storeCategoryText => 'Text';
+
+  @override
+  String get storeCategoryLlm => 'KI-Modelle';
+
+  @override
+  String get storeCategorySystem => 'System';
+
+  @override
+  String get storeCategoryAuth => 'Authentifizierung';
+
+  @override
+  String get storeCategoryStorage => 'Speicher';
+
+  @override
+  String get storeCategoryChannel => 'Kanäle';
+
+  @override
+  String get storeCategoryWeb => 'Web';
+
+  @override
+  String get storeCategoryOrchestrator => 'Orchestrierung';
+
   @override
   String storeNResults(int n) {
     return '$n Treffer';
@@ -596,6 +632,11 @@ class AppLocalizationsDe extends AppLocalizations {
     return '$name hinzugefügt — $n $_temp0.';
   }
 
+  @override
+  String storeProviderAddedZeroToast(String name) {
+    return '$name ist eingetragen, aber der Server hat noch keine Capabilities geliefert. Öffne Einstellungen → MCP-Clients, um Discovery erneut zu versuchen oder den Server zu prüfen.';
+  }
+
   @override
   String storeProviderAddFailed(String name, String error) {
     return '$name konnte nicht hinzugefügt werden: $error';

lib/l10n/app_localizations_en.dart

@@ -394,17 +394,53 @@ class AppLocalizationsEn extends AppLocalizations {
   String get storeStatusAll => 'All';
 
   @override
-  String get storeStatusPublished => 'Published';
+  String get storeStatusPublished => 'stable';
 
   @override
-  String get storeStatusAlpha => 'Alpha';
+  String get storeStatusAlpha => 'experimental';
 
   @override
-  String get storeStatusPlanned => 'Planned';
+  String get storeStatusPlanned => 'coming soon';
 
   @override
   String get storeInstalledOnly => 'Installed';
 
+  @override
+  String get storeCategoryLabel => 'Category';
+
+  @override
+  String get storeCategoryAll => 'All categories';
+
+  @override
+  String get storeCategoryBridge => 'Connectors';
+
+  @override
+  String get storeCategoryDebug => 'Sample modules';
+
+  @override
+  String get storeCategoryText => 'Text';
+
+  @override
+  String get storeCategoryLlm => 'AI models';
+
+  @override
+  String get storeCategorySystem => 'System';
+
+  @override
+  String get storeCategoryAuth => 'Authentication';
+
+  @override
+  String get storeCategoryStorage => 'Storage';
+
+  @override
+  String get storeCategoryChannel => 'Channels';
+
+  @override
+  String get storeCategoryWeb => 'Web';
+
+  @override
+  String get storeCategoryOrchestrator => 'Orchestration';
+
   @override
   String storeNResults(int n) {
     String _temp0 = intl.Intl.pluralLogic(
@@ -613,6 +649,11 @@ class AppLocalizationsEn extends AppLocalizations {
     return 'Added $name — $n federated $_temp0.';
   }
 
+  @override
+  String storeProviderAddedZeroToast(String name) {
+    return '$name registered, but the server returned no capabilities yet. Open Settings → MCP Clients to retry discovery or check the server.';
+  }
+
   @override
   String storeProviderAddFailed(String name, String error) {
     return 'Could not add $name: $error';