Suite6 + P8: Comprehensive task tests + Roborazzi scaffolding

Suite6_ComprehensiveTaskTests ports iOS tests not covered by Suite5/10
(priority/frequency picker variants, custom intervals, completion history,
edge cases).

Roborazzi screenshot-regression scaffolding in place but gated with @Ignore
until pipeline is wired — first `recordRoborazziDebug` run needs manual
golden-image review. See docs/screenshot-tests.md for enablement steps.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/screenshot-tests.md

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+# Roborazzi screenshot regression tests (P8)
+
+Roborazzi is a screenshot-diff testing tool purpose-built for Jetpack /
+Compose Multiplatform. It runs on the Robolectric-backed JVM unit-test
+classpath, so no emulator or physical device is required — perfect for
+CI and for catching UI regressions on every PR.
+
+## Why screenshot tests?
+
+Unit tests assert logic; instrumentation tests assert user-visible
+behaviour. Neither reliably catches *design* regressions: a colour drift
+in `Theme.kt`, a typography scale change, an accidental padding edit.
+Screenshot tests close that gap by diffing pixel output against a
+committed golden set.
+
+## What we cover
+
+The initial matrix (see `composeApp/src/androidUnitTest/.../ScreenshotTests.kt`)
+is intentionally conservative:
+
+| Surface | Themes | Modes | Total |
+|---|---|---|---|
+| Login | Default · Ocean · Midnight | light · dark | 6 |
+| Tasks | Default · Ocean · Midnight | light · dark | 6 |
+| Residences | Default · Ocean · Midnight | light · dark | 6 |
+| Profile | Default · Ocean · Midnight | light · dark | 6 |
+| Theme palette | Default · Ocean · Midnight | light · dark | 6 |
+| Complete task | Default · Ocean · Midnight | light · dark | 6 |
+| **Total** | | | **36** |
+
+The full 11-theme matrix (132+ images) is deliberately deferred — the
+cost of reviewer approval on every image outweighs the marginal cover.
+
+Each test renders a *showcase* composable (pure Material3 primitives)
+rather than the full production screen. That keeps Roborazzi hermetic:
+no DataManager, no Ktor client, no ViewModel. A regression in
+`Theme.kt`'s colour scheme will still surface because the showcases
+consume every colour slot the real screens use.
+
+## Commands
+
+```bash
+# Record a fresh golden set (do this on first setup and after intentional UI changes)
+./gradlew :composeApp:recordRoborazziDebug
+
+# Verify current UI matches the golden set (fails the build on drift)
+./gradlew :composeApp:verifyRoborazziDebug
+
+# Generate side-by-side diff images (useful for review)
+./gradlew :composeApp:compareRoborazziDebug
+```
+
+Output lands under `composeApp/build/outputs/roborazzi/`.
+
+## Golden-image workflow
+
+Roborazzi goldens are *not* auto-committed. The workflow is:
+
+1. Developer changes a composable (intentionally or otherwise).
+2. CI runs `verifyRoborazziDebug` and fails on any drift.
+3. Developer inspects the diff locally via `compareRoborazziDebug` or
+   from the CI artifact.
+4. If the drift is intentional, regenerate via
+   `recordRoborazziDebug` and commit the new PNGs inside the PR so the
+   reviewer explicitly sign-offs on each image change.
+5. If the drift is a regression, fix the composable and re-run.
+
+**Reviewer checklist:** every committed `.png` under the roborazzi output
+dir is an intentional design decision. Scrutinise as carefully as you
+would scrutinise the code change it accompanies.
+
+## Adding a new screenshot test
+
+```kotlin
+@Test
+fun mySurface_default_light() = runScreen(
+    name = "my_surface_default_light",
+    theme = AppThemes.Default,
+    darkTheme = false,
+) {
+    MySurfaceShowcase()
+}
+```
+
+Add the corresponding dark-mode and other-theme variants, then run
+`recordRoborazziDebug` to generate the initial PNGs.
+
+## Known limitations
+
+- Roborazzi requires `@GraphicsMode(Mode.NATIVE)` — the Robolectric
+  version in this repo (4.14.1) supports it.
+- The test runner uses a fixed device qualifier (`w360dp-h800dp-mdpi`).
+  If you change this, every golden must be regenerated.
+- `captureRoboImage` only captures the composable tree, not window
+  chrome (status bar, navigation bar). That's intentional — chrome
+  is owned by the OS, not our design system.
+
+## References
+
+- Upstream: https://github.com/takahirom/roborazzi
+- Matrix rationale: see commit message on `P8: Roborazzi screenshot
+  regression test scaffolding`.