Republish setup: fastlane + Forgejo CI, signing/version fixes, Play-policy link

- support_page: repoint comunes.org link to project page (Play re-approval)
- build.gradle: conditional release signing (debug fallback), versionCode/Name
  from pubspec, drop duplicate google-services plugin
- pubspec: version 1.10.0+10 (versionCode must exceed last uploaded)
- track AndroidManifest.xml (no secrets in it)
- fastlane: Appfile/Fastfile (deploy_play/deploy_metadata/promote_production) +
  Gemfile + es/en/gl store metadata
- .forgejo: ci.yml (analyze+test) + release.yml (tag v* -> signed AAB -> Play internal)
- README + RELEASE.md

.forgejo/workflows/ci.yml

@@ -0,0 +1,54 @@
+# Per-push gate for git.comunes.org (Forgejo Actions): analyze + tests.
+# Flutter pinned to the developer toolchain (3.41.9).
+#
+# NOTE: `runs-on` must match a label your Forgejo runner registered with.
+# We check out with plain git (a `run:` step) instead of actions/checkout@v4:
+# the cirruslabs/flutter image has no Node.js, and JS-based actions need it
+# ("exec: node: not found"). Manual checkout keeps the workflow Node-free.
+
+name: ci
+
+on:
+  push:
+    branches: ['**']
+  pull_request:
+
+jobs:
+  analyze:
+    runs-on: docker
+    container:
+      image: ghcr.io/cirruslabs/flutter:3.41.9
+    steps:
+      - name: Checkout
+        env:
+          TOKEN: ${{ github.token }}
+        run: |
+          git config --global --add safe.directory '*'
+          git init -q .
+          git remote add origin "http://x-access-token:${TOKEN}@forgejo:3000/${GITHUB_REPOSITORY}.git"
+          git fetch -q --depth 1 origin "${GITHUB_SHA}"
+          git checkout -q FETCH_HEAD
+      - run: flutter pub get
+      - name: Generate code (json_serializable)
+        run: dart run build_runner build --delete-conflicting-outputs
+      - run: flutter analyze
+
+  test:
+    runs-on: docker
+    container:
+      image: ghcr.io/cirruslabs/flutter:3.41.9
+    steps:
+      - name: Checkout
+        env:
+          TOKEN: ${{ github.token }}
+        run: |
+          git config --global --add safe.directory '*'
+          git init -q .
+          git remote add origin "http://x-access-token:${TOKEN}@forgejo:3000/${GITHUB_REPOSITORY}.git"
+          git fetch -q --depth 1 origin "${GITHUB_SHA}"
+          git checkout -q FETCH_HEAD
+      - run: flutter pub get
+      - name: Generate code + test
+        run: |
+          dart run build_runner build --delete-conflicting-outputs
+          flutter test