feat(release): automate store publishing (fastlane supply + GitLab CI) and F-Droid recipe

- fastlane: Appfile/Fastfile/Gemfile with deploy_play lane (AAB -> Play internal track)
- CI: tag-gated build:android (signed AAB/APK from CI secrets) + deploy:play jobs
- F-Droid: fdroiddata build recipe at docs/fdroid/org.comunes.tane.yml
- Play compliance: Data Safety / content-rating answer sheet (docs/legal/internal)
- docs/release.md: automated tag-triggered flow, dedicated tane-upload keystore
- pubspec: description now mentions the market, not just the inventory

apps/app_seeds/.gitignore

@@ -43,3 +43,10 @@ app.*.map.json
 /android/app/debug
 /android/app/profile
 /android/app/release
+
+# Release automation (fastlane supply). Credentials come from CI secrets or a
+# gitignored local file; generated reports are not tracked.
+/play-service-account.json
+/fastlane/report.xml
+/fastlane/Preview.html
+/Gemfile.lock