Final batch of the 250-line sweep. `check_file_length.sh --all` exits 0: every
file in the repo is at or under 250 lines.
github_mirror_screen.dart 391 -> 205 (+ actions, client_id_dialog parts)
foodbank_service.dart 314 -> 209 (+ foodbank_service_manual part)
settings_screen.dart 286 -> 237 (+ settings_kcal_goal part)
firebase_backend.dart 282 -> 100 (+ firebase_client.dart)
Three of the four are `part` files rather than separate libraries, and that is
forced rather than stylistic: the moved code drives private state
(`_busy`, `_status`, the text controllers) and calls private helpers
(`_readBank`, `_normalize`), none of which are visible across a library
boundary in Dart. Widening them to public just to split a file would leak
internals the rest of the app has no business calling.
Within those parts, mixins rather than extensions, for a concrete reason: an
extension is not a subclass of `State`, so calling `setState` from one is an
`invalid_use_of_protected_member`. Fields the State must own (the controllers
it creates and disposes) stay declared there and are reached through abstract
getters.
`firebase_client.dart` is a real library split -- opening an authenticated
client has no private coupling to the keystore-backed account record, only to
its public API. The one exception, dropping the account marker without setting
the opt-out flag, became `forgetAccountMarker()` rather than exposing the
secure store.
Verified: flutter test 555 (unchanged), flutter analyze clean, 707 Python
tests / 100% branch coverage, check_patch_targets 0, pre-commit clean,
check_file_length.sh --all exit 0.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RA9ynjqXPnexRQnR5oAuCC
