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

pubspec.yaml

@@ -1,5 +1,8 @@
 name: fires_flutter
 description: All Against Fire
+# MAJOR.MINOR.PATCH+versionCode — Flutter maps +CODE to Android versionCode.
+# Must be strictly greater than the highest versionCode ever uploaded to Play.
+version: 1.10.0+10
 
 environment:
   sdk: ">=3.0.0 <4.0.0"