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/main.dart

@@ -26,7 +26,7 @@ import 'widgets/widgets.dart';
 /// Studio's own build version. Bump on every UI commit so the
 /// running app self-identifies — visible in the sidebar header
 /// and quick-glance proof that you're seeing the current build.
-const String kStudioVersion = '0.30.0';
+const String kStudioVersion = '0.31.0';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();