feat(studio): daily Today-Hero proposal pipeline (v0.31.0)

Cross-store research (Apple, Play, Steam, Docker, VS Code,
Chrome Web Store, Flathub) consistently rewards editorial
curation over algorithmic recommendations — but manual
copywriting per release does not survive a solo-dev cadence.
This commit lands a daily-build pipeline so the Today-Hero
card stays fresh without operator hand-edits per release.

Pipeline shape (full design in docs/today-pipeline.md):

1. tools/today/collect.sh aggregates "what happened in the
   last 24 hours" across the F∆I monorepos: git log per repo,
   store-index seed.yaml diffs, architecture/system-gaps doc
   changes, Studio release tags, and (opt-in) audit-log
   highlights. Outputs plain text.

2. tools/today/propose.sh feeds the signal summary plus
   prompt.template.md to the operator's already-configured
   System-AI (Ollama default; OpenAI-compatible endpoints
   work via env-var override). Drafts N candidate stories as
   YAML files under ~/.fai/today/proposals/<date>/.

3. tools/today/accept.sh validates a chosen candidate against
   the today/v1 schema and the no-marketing-speak banned-word
   list, then atomic-renames it into ~/.fai/today/active.yaml.

4. Studio reads active.yaml at store-page init via the new
   TodayStoryLoader (lib/data/today_story_loader.dart). On any
   failure (file missing, schema mismatch, banned-words hit,
   parse error) it falls back to the compiled-in
   _kFallbackTodayStory so KRITIS deployments and fresh
   installs always render something sensible.

Trust + audit:
- All proposed and accepted stories live as plain YAML on disk.
- The pipeline calls only the operator's already-configured
  System-AI; it never reaches a CMS, never phones home, works
  air-gapped if the System-AI does.
- The bash accept gate AND the Dart loader both enforce the
  banned-word list — a hand-edited active.yaml that bypassed
  the shell still won't reach the UI.
- Removing the cron entry disables the pipeline; Studio falls
  back to the const story and continues to work.

Cron / launchd / systemd recipes documented in
tools/today/README.md.

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

lib/pages/store.dart

@@ -10,6 +10,7 @@ import 'package:flutter_markdown/flutter_markdown.dart';
 
 import '../data/hub.dart';
 import '../data/system_actions.dart';
+import '../data/today_story_loader.dart';
 import '../l10n/app_localizations.dart';
 import '../theme/theme.dart';
 import '../theme/tokens.dart';
@@ -38,6 +39,11 @@ class _StorePageState extends State<StorePage> {
   /// session. Not persisted — the next Studio launch shows it
   /// again so a release-bumped story has a chance to be seen.
   bool _todayDismissed = false;
+  /// Loaded once at init from `~/.fai/today/active.yaml`; falls
+  /// back to the compiled-in story when the pipeline hasn't
+  /// produced an accepted candidate yet.
+  late final TodayStoryData _todayStory =
+      TodayStoryLoader.loadOrFallback(_kFallbackTodayStory);
   late Future<List<StoreItem>> _future;
 
   /// Active UI locale, read from the app-wide MaterialApp
@@ -265,11 +271,11 @@ class _StorePageState extends State<StorePage> {
                     children: [
                       if (showToday) ...[
                         _StoreTodayHero(
-                          story: _kCurrentTodayStory,
+                          story: _todayStory,
                           locale: _locale,
                           onDismiss: () =>
                               setState(() => _todayDismissed = true),
-                          onCta: _kCurrentTodayStory.cta == _TodayCta.openSettings
+                          onCta: _todayStory.cta == TodayCta.openSettings
                               ? () => FaiSettingsDialog.show(context)
                               : null,
                         ),
@@ -1934,47 +1940,11 @@ class _ScreenshotPlaceholder extends StatelessWidget {
   }
 }
 
-/// Editorial action attached to a `_TodayStory`. Kept as an
-/// enum (not a closure) so the story list stays `const` and
-/// thus shippable as a frozen, audit-friendly artefact.
-enum _TodayCta { openSettings }
-
-/// Editorial story shown in the Today-hero strip. One story
-/// is curated per release in [_kCurrentTodayStory] — operators
-/// who launch Studio see the same narrative until the next
-/// version bump. Bilingual content is shipped inline so KRITIS
-/// deployments don't need to pull translations from a CMS.
-class _TodayStory {
-  final String badgeEn;
-  final String badgeDe;
-  final String titleEn;
-  final String titleDe;
-  final String bodyEn;
-  final String bodyDe;
-  final String ctaLabelEn;
-  final String ctaLabelDe;
-  final IconData icon;
-  final _TodayCta cta;
-
-  const _TodayStory({
-    required this.badgeEn,
-    required this.badgeDe,
-    required this.titleEn,
-    required this.titleDe,
-    required this.bodyEn,
-    required this.bodyDe,
-    required this.ctaLabelEn,
-    required this.ctaLabelDe,
-    required this.icon,
-    required this.cta,
-  });
-}
-
-/// The story shown by Studio v0.30.x. Update when the
-/// release-narrative changes — this is the editorial role of
-/// the App Store Today tab, kept lightweight: one story, one
-/// CTA, refreshed per release.
-const _TodayStory _kCurrentTodayStory = _TodayStory(
+/// Compiled-in fallback story shown when
+/// `~/.fai/today/active.yaml` is absent or fails schema
+/// validation. The pipeline operator can override at any time
+/// without recompiling Studio — see docs/today-pipeline.md.
+const TodayStoryData _kFallbackTodayStory = TodayStoryData(
   badgeEn: 'CAPABILITY FEDERATION',
   badgeDe: 'CAPABILITY-FEDERATION',
   titleEn: 'Two MCP servers away from a richer hub',
@@ -1986,7 +1956,7 @@ const _TodayStory _kCurrentTodayStory = _TodayStory(
   ctaLabelEn: 'Open MCP settings',
   ctaLabelDe: 'MCP-Einstellungen öffnen',
   icon: Icons.hub_outlined,
-  cta: _TodayCta.openSettings,
+  cta: TodayCta.openSettings,
 );
 
 /// Editorial hero strip — the first surface a browsing operator
@@ -1995,7 +1965,7 @@ const _TodayStory _kCurrentTodayStory = _TodayStory(
 /// bullets. Auto-hides whenever a filter is active so a
 /// purposeful search isn't pushed below the fold.
 class _StoreTodayHero extends StatelessWidget {
-  final _TodayStory story;
+  final TodayStoryData story;
   final String locale;
   final VoidCallback onDismiss;
   /// CTA action — null hides the button. Wired by the parent