todo, home_inventory, diet-guard and wake-alarm each carried the OAuth
device-flow client and the modal that drives it -- ~650 lines, with two
pairs byte-for-byte identical (todo/home_inventory's clients, and
diet-guard/wake-alarm's dialogs).
Deliberately its own package rather than part of `sync_settings_ui`. That
package is Firebase-only by an explicit 2026-08-12 decision recorded as
"do not re-add a GitHub section without kuhy asking again", so folding a
GitHub flow into it would reverse a standing decision. The GitHub mirror
in these apps is legacy-but-load-bearing code that was explicitly not
authorised for deletion, so it gets its own home instead of being merged
into the Firebase path or dropped.
One behaviour change, made once here instead of four times: the dialog
catches `on Object`, not `on Exception`. An `Error` is not an `Exception`
in Dart, so `ArgumentError` -- notably from URI parsing -- escaped
`_poll()` and left the dialog spinning on "Waiting for authorization…"
forever with nothing shown. That is the same trap that silently killed the
Firebase sync tick across these apps in 2026-08. A test pins it with a
mock that throws an Error rather than an Exception, so it cannot regress
back to `on Exception` unnoticed.
20 tests, 100% line coverage, clean under very_good_analysis, with the
same CI gate the other Dart package holds. Consumers are migrated
separately so each app's own suite gates its own swap.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01U4Rj3s7K2qzrLNgJqqPhno
