Replaces the stopgap (53f87f5) that committed
lib/storage/drift/offband_database.g.dart to green CI. Restores the
repo's "generated files are not committed" convention:
- dropped the .gitignore negation; the .g.dart is gitignored + untracked
(git rm --cached, working copy kept)
- added `dart run build_runner build --delete-conflicting-outputs`
immediately after `flutter pub get` in every Dart job: flutter_dart
(analyze), build.yml (all 6), release-signed (android-signed),
deploy-web (before build_pipe)
- keeps the drift_dev 2.34.0 / drift 2.34.2 / build_runner ^2.15.1 pins
from the stopgap for deterministic generation
Verified locally on the bench toolchain (3.44.1): deleted the working
.g.dart, ran build_runner from scratch (regenerated cleanly), confirmed
the generated file passes `dart format --set-exit-if-changed` and full
`flutter analyze --fatal-infos --fatal-warnings` is clean with the file
generated (not tracked).
For #335 / PR #348. Agent: SapphireCompass (session 8d755b5e)