chore(fdroid): single-source fastlane metadata + reproducible-build prep

Make fastlane/metadata/android/ the single source of truth for store
listing metadata, consumed directly by the official F-Droid repo and
transformed into the self-hosted repo's localized layout at release time.

- Move fdroid-metadata/<appid>/<locale>/ -> fastlane/metadata/android/<locale>/
  (git-tracked renames: summary->short_description, description->full_description,
  + title.txt, images/icon.png, images/phoneScreenshots/); keep the app-level
  .yml control file for the self-hosted `fdroid update`.
- Add scripts/fastlane_to_fdroid_localized.sh (fastlane -> F-Droid localized,
  incl. changelogs) and scripts/sync_changelog_to_fastlane.sh (CHANGELOG.md ->
  fastlane changelog); verified byte-identical to the previous metadata.
- release.yaml: build self-hosted metadata from the fastlane tree and sync the
  per-version changelog before the transform (one changelog source for both
  channels).
- Disable AGP VCS-info embedding on release builds (vcsInfo { include = false })
  so builds reproduce byte-for-byte vs the distributed APK — the only file that
  otherwise differed (META-INF/version-control-info.textproto). Effective from
  the next release.
- Add docs/fdroid-official/ (draft fdroiddata recipe: reproducible build +
  AllowedAPKSigningKeys + Binaries + notes).
- Repoint README screenshots/icon, update docs/README + RELEASING, and skip the
  Android build on fastlane-only changes (ci.yaml).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/README.md

@@ -12,7 +12,9 @@ Where to look for what:
 | [`../.planning/STATE.md`](../.planning/STATE.md) | Snapshot of where development currently stands |
 | [`superpowers/specs/`](superpowers/specs/) | The original design spec (2026-06-08) — historical record, not updated |
 | [`superpowers/plans/`](superpowers/plans/) | Per-milestone implementation plans with task checklists — historical record of how each slice was built, including provider lessons learned |
-| [`../fdroid-metadata/`](../fdroid-metadata/) | F-Droid/fastlane store metadata: descriptions, icon, screenshots (DE + EN) |
+| [`../fastlane/metadata/android/`](../fastlane/metadata/android/) | Store metadata (single source of truth): descriptions, title, icon, screenshots (DE + EN). Harvested directly by the official F-Droid repo; transformed into the self-hosted repo layout at release time by [`../scripts/fastlane_to_fdroid_localized.sh`](../scripts/fastlane_to_fdroid_localized.sh) |
+| [`../fdroid-metadata/`](../fdroid-metadata/) | App-level F-Droid control file (`*.yml`: Categories, License, links) for the self-hosted repo's `fdroid update` |
+| [`fdroid-official/`](fdroid-official/) | Draft recipe + notes for publishing to the **official** F-Droid repo (reproducible build + developer-signed binary) |
 
 Conventions: plans and specs under `superpowers/` are point-in-time
 artifacts of the agentic workflow that built each milestone — they get