docs(fdroid): fix recipe for F-Droid CI (build chown, checkupdates, schema)

- chown /opt/flutter to vagrant (build runs as non-root; fixes cache write)
- AutoUpdateMode: Version (drop invalid 'v%v' per schema)
- UpdateCheckMode: Tags v[\d.]+ + UpdateCheckData reading version from
  apps/app_seeds/pubspec.yaml (Flutter versionCode isn't a literal in gradle)
Validated locally: schema, lint, checkupdates (exit 0), and flutter build as vagrant.

docs/fdroid/org.comunes.tane.yml

@@ -1,23 +1,3 @@
-# F-Droid metadata for Tane (org.comunes.tane).
-#
-# This is the source of truth for the fdroiddata merge request. To submit:
-#   1. Fork https://gitlab.com/fdroid/fdroiddata
-#   2. Copy this file to  metadata/org.comunes.tane.yml
-#   3. Validate locally:   fdroid lint org.comunes.tane
-#                          fdroid build -v -l org.comunes.tane
-#   4. Open the MR.
-#
-# Prerequisites (see docs/release.md):
-#   - The source repo below must be publicly clonable without auth.
-#   - Each release is a signed git tag `v<version>` (UpdateCheckMode: Tags).
-#   - F-Droid builds and signs the APK with ITS OWN key, so the F-Droid build
-#     and the Google Play build have different signatures and cannot cross-update.
-#
-# NOTE: Flutter-on-F-Droid builds are finicky. Pin the Flutter version to the
-# developer toolchain (3.41.9) and re-run `fdroid build` after every bump. This
-# recipe accounts for the monorepo layout (pub workspace root at repo root, app
-# at apps/app_seeds) and the generated code (slang i18n + Drift via build_runner).
-
 Categories:
   - Inventory
   - Market & Price
@@ -43,22 +23,22 @@ Builds:
     sudo:
       - apt-get update
       - apt-get install -y git unzip xz-utils
-      # Pin Flutter to the developer toolchain; keep in sync with .gitlab-ci.yml.
       - git clone --depth 1 -b 3.41.9 https://github.com/flutter/flutter.git /opt/flutter
-      - git config --global --add safe.directory /opt/flutter
+      - chown -R vagrant:vagrant /opt/flutter
     output: build/app/outputs/flutter-apk/app-release.apk
     prebuild:
       - export PATH="/opt/flutter/bin:$PATH"
+      - git config --global --add safe.directory /opt/flutter
       - flutter config --no-analytics
       - flutter pub get
-      # Generated sources: i18n (slang) then Drift/other codegen (build_runner).
       - dart run slang
       - dart run build_runner build --delete-conflicting-outputs
     build:
       - export PATH="/opt/flutter/bin:$PATH"
       - flutter build apk --release
 
-AutoUpdateMode: Version v%v
-UpdateCheckMode: Tags
+AutoUpdateMode: Version
+UpdateCheckMode: Tags v[\d.]+
+UpdateCheckData: apps/app_seeds/pubspec.yaml|version:\s*[\d.]+\+(\d+)|apps/app_seeds/pubspec.yaml|version:\s*([\d.]+)\+
 CurrentVersion: 0.1.0
 CurrentVersionCode: 2