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

android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,47 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="org.comunes.fires">
+
+    <!-- The INTERNET permission is required for development. Specifically,
+         flutter needs it to communicate with the running application
+         to allow setting breakpoints, to provide hot reload, etc.
+    -->
+    <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
+    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
+
+    <!-- io.flutter.app.FlutterApplication is an android.app.Application that
+         calls FlutterMain.startInitialization(this); in its onCreate method.
+         In most cases you can leave this as-is, but you if you want to provide
+         additional functionality it is fine to subclass or reimplement
+         FlutterApplication and put your custom class here. -->
+    <application
+        android:label="@string/app_name"
+        android:icon="@mipmap/launch_image"
+        android:enableOnBackInvokedCallback="true">
+        <meta-data
+            android:name="flutterEmbedding"
+            android:value="2" />
+        <activity
+            android:name=".MainActivity"
+            android:exported="true"
+            android:launchMode="singleTop"
+            android:theme="@style/LaunchTheme"
+            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density"
+            android:hardwareAccelerated="true"
+            android:windowSoftInputMode="adjustResize">
+            <!-- This keeps the window background of the activity showing
+                 until Flutter renders its first frame. It can be removed if
+                 there is no splash screen (such as the default splash screen
+                 defined in @style/LaunchTheme). -->
+            <!-- <meta-data
+                android:name="io.flutter.app.android.SplashScreenUntilFirstFrame"
+                android:value="true" /> -->
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN"/>
+                <category android:name="android.intent.category.LAUNCHER"/>
+                <action android:name="FLUTTER_NOTIFICATION_CLICK" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
+        </activity>
+    </application>
+</manifest>