Adds instrumented Compose UI tests for the screens #250/#274 left uncovered,
so lane 6's ui-package coverage ratchet (#251, >=95%) can pass:
- ColorSwatchRow (compose/format): none entry + swatch rendering, selection
callbacks, and selected-state semantics.
- LockScreen: locked title/body, optional error text, unlock callback.
- AddAnotherAccountScreen: confirmation + both onboarding choices.
- SignatureEditScreen: real ViewModel over an in-memory Room-backed
SignatureRepository — new-vs-edit title, create/update round-trips.
- ReportReviewScreen: real ViewModel over a file-backed ReportStore (submitter
stubbed disabled) — disclaimer/fields render, Submit gated on comment length
+ email validity, discard deletes and leaves.
- AppPasswordSetupScreen: real ViewModel over FakeAccountRepository — provider
chrome + credential add, and the app-password help link asserted via
Espresso-Intents (mirrors AccountPickerScreenTest) so no real browser opens.
All 23 tests pass locally on an API 36 emulator.
Closes#275
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>