feat(theme): persist useWallpaperColors preference + dynamic ColorScheme branching

app/src/main/java/de/pyryco/mobile/MainActivity.kt

@@ -59,13 +59,15 @@ class MainActivity : ComponentActivity() {
             val appPreferences = koinInject<AppPreferences>()
             val themeMode by appPreferences.themeMode
                 .collectAsStateWithLifecycle(initialValue = ThemeMode.SYSTEM)
+            val useWallpaperColors by appPreferences.useWallpaperColors
+                .collectAsStateWithLifecycle(initialValue = false)
             val darkTheme =
                 when (themeMode) {
                     ThemeMode.SYSTEM -> isSystemInDarkTheme()
                     ThemeMode.LIGHT -> false
                     ThemeMode.DARK -> true
                 }
-            PyrycodeMobileTheme(darkTheme = darkTheme) {
+            PyrycodeMobileTheme(darkTheme = darkTheme, dynamicColor = useWallpaperColors) {
                 Scaffold(modifier = Modifier.fillMaxSize()) { innerPadding ->
                     val paired: Boolean? by produceState<Boolean?>(
                         initialValue = null,

app/src/main/java/de/pyryco/mobile/data/preferences/AppPreferences.kt

@@ -28,8 +28,16 @@ class AppPreferences(
         dataStore.edit { prefs -> prefs[THEME_MODE] = mode.name }
     }
 
+    val useWallpaperColors: Flow<Boolean> =
+        dataStore.data.map { prefs -> prefs[USE_WALLPAPER_COLORS] ?: false }
+
+    suspend fun setUseWallpaperColors(enabled: Boolean) {
+        dataStore.edit { prefs -> prefs[USE_WALLPAPER_COLORS] = enabled }
+    }
+
     private companion object {
         val PAIRED_SERVER_EXISTS = booleanPreferencesKey("paired_server_exists")
         val THEME_MODE = stringPreferencesKey("theme_mode")
+        val USE_WALLPAPER_COLORS = booleanPreferencesKey("use_wallpaper_colors")
     }
 }

app/src/test/java/de/pyryco/mobile/data/preferences/AppPreferencesTest.kt

@@ -76,4 +76,21 @@ class AppPreferencesTest {
             dataStore.edit { it[stringPreferencesKey("theme_mode")] = "PURPLE" }
             assertEquals(ThemeMode.SYSTEM, prefs.themeMode.first())
         }
+
+    @Test
+    fun useWallpaperColors_defaultsToFalse() =
+        runBlocking {
+            assertEquals(false, prefs.useWallpaperColors.first())
+        }
+
+    @Test
+    fun setUseWallpaperColors_roundTripsBothValues() =
+        runBlocking {
+            prefs.setUseWallpaperColors(false)
+            assertEquals(false, prefs.useWallpaperColors.first())
+            prefs.setUseWallpaperColors(true)
+            assertEquals(true, prefs.useWallpaperColors.first())
+            prefs.setUseWallpaperColors(false)
+            assertEquals(false, prefs.useWallpaperColors.first())
+        }
 }

docs/knowledge/INDEX.md

@@ -13,7 +13,7 @@ One-line pointers to evergreen docs. Per-ticket implementation notes live under
 - [Data model](features/data-model.md) — `Conversation` / `Session` / `Message` schema in `data/model/`; shared shape across mobile, Discord, and pyrycode CLI consumers. Sentinel `DefaultScratchCwd` co-lives in `Conversation.kt` as the single-source-of-truth marker for unbound-workspace conversations. `Conversation.isSleeping: Boolean = false` (#20) is derived in Phase 1 and wire-parsed in Phase 4. `Conversation.archived: Boolean = false` (#93) is the authoritative archive bit — flipped by `archive(id)`, parsed from the wire in Phase 4.
 - [Conversation repository](features/conversation-repository.md) — `ConversationRepository` interface + `ConversationFilter` (`All` / `Channels` / `Discussions` / `Archived` since #93), `ThreadItem` (`MessageItem` / `SessionBoundary`), `BoundaryReason`; data-layer seam every UI tier binds to. Phase 1 binding is the in-memory `FakeConversationRepository`; the `observeConversations` projection also stamps the derived `Conversation.isSleeping` flag (#20). Filter matrix (#93): `All` returns everything including archived; `Channels` / `Discussions` carry an explicit `!archived` clause; `Archived` returns archived rows regardless of `isPromoted`. `archive(id)` since #93 flips the flag instead of removing the entry; `unarchive(id)` since #96 is the symmetric inverse (silent-idempotent flag flip back to `false`, same `unknown(id)` throw on missing).
 - [Dependency injection](features/dependency-injection.md) — Koin scaffold; single `appModule` at `di/AppModule.kt`, `startKoin` owned by `PyryApp.onCreate`. Downstream tickets append `single`/`viewModel` lines.
-- [App preferences](features/app-preferences.md) — `AppPreferences` wrapper over a shared `DataStore<Preferences>` (file `app_prefs`); typed `Flow<T>` reads + `suspend` setters for non-secret app state. Keys: `pairedServerExists` (#11/#12/#13), `themeMode: Flow<ThemeMode>` (#86 — `stringPreferencesKey("theme_mode")` holding the enum's `.name`; `entries.firstOrNull { it.name == stored } ?: SYSTEM` fallback for both absent + unparseable; consumed reactively at `MainActivity`'s `setContent` root to resolve `PyrycodeMobileTheme(darkTheme = …)` and inside `composable(Routes.SETTINGS)` to drive the Theme row subtitle).
+- [App preferences](features/app-preferences.md) — `AppPreferences` wrapper over a shared `DataStore<Preferences>` (file `app_prefs`); typed `Flow<T>` reads + `suspend` setters for non-secret app state. Keys: `pairedServerExists` (#11/#12/#13), `themeMode: Flow<ThemeMode>` (#86 — `stringPreferencesKey("theme_mode")` holding the enum's `.name`; `entries.firstOrNull { it.name == stored } ?: SYSTEM` fallback for both absent + unparseable; consumed reactively at `MainActivity`'s `setContent` root to resolve `PyrycodeMobileTheme(darkTheme = …)` and inside `composable(Routes.SETTINGS)` to drive the Theme row subtitle), `useWallpaperColors: Flow<Boolean>` (#88 — `booleanPreferencesKey("use_wallpaper_colors")`, default `false`; collected as a sibling to `themeMode` at `setContent`'s root and forwarded into `PyrycodeMobileTheme(dynamicColor = …)`, whose internal `Build.VERSION.SDK_INT >= S` gate at `Theme.kt:275` handles the pre-S fall-through to the brand palette; matching `setUseWallpaperColors(...)` setter is wired by sibling ticket #89's visible Material You switch row).
 - [ConversationRow](features/conversation-row.md) — stateless M3 `ListItem`-based row consuming `Conversation` + `Message?`; auto-name fallback branched on `isPromoted`, whitespace-normalized 2-line preview, kotlinx-datetime relative-time bucketing (`just now` / `Nm ago` / `Nh ago` / `Yesterday` / `Nd ago` / abbreviated date). Headline is a `Row` with two natural-width decorations: workspace label (#19, trailing) and sleeping-session dot (#20, leading — 8.dp `Box` filled with `colorScheme.outline`, gated on `Conversation.isSleeping`). Optional `onLongClick: (() -> Unit)? = null` (#25) switches the modifier chain from `Modifier.clickable` to `Modifier.combinedClickable` so callers can attach long-press affordances without fanning a screen-specific concept into the shared primitive. Since #68 the `ListItem` carries a `leadingContent = { ConversationAvatar(conversation) }` slot. Shared between the #46 channel list and the discussions drilldown.
 - [ConversationAvatar](features/conversation-avatar.md) — 40dp leading bubble for `Conversation`-backed rows (#68); deterministic hash-based palette selection via `Math.floorMod(name.hashCode(), 3)` across `primary`/`secondary`/`tertiary` `*-container` pairs, 2-letter lowercase initials from `deriveInitials(name, fallback = conversation.id)` (first letter of first two words after splitting on `[^\p{L}\p{N}]+`; single-word and null/blank fallbacks pad with `'?'`). `paletteIndexFor` and `deriveInitials` are `internal` non-`@Composable` helpers so `./gradlew test` covers them as plain JUnit. Decorative — no `contentDescription`.
 - [DiscussionPreviewRow](features/discussion-preview-row.md) — stateless preview-row primitive for the inline Recent-discussions section (#69); `Column` of titleMedium title (auto-fallback `R.string.untitled_discussion`), 2-line bodyMedium placeholder body (`R.string.discussion_preview_placeholder_body` — real previews deferred until the data layer surfaces a per-`Conversation` last-message projection), and a single-line `<workspace> · <relative-time>` meta `Text` rendering an `AnnotatedString` with `SpanStyle(fontFamily = FontFamily.Monospace)` applied only to the workspace fragment. Workspace label diverges from `ConversationRow.condenseWorkspace`: always returns a string, falls back to `R.string.discussion_preview_workspace_scratch` ("scratch") for `DefaultScratchCwd` *and* for empty trailing segments. Sole call site is `RecentDiscussionsSection` inside `ChannelListScreen`; shares the `formatRelativeTime` helper extracted into `ui/conversations/components/RelativeTime.kt` (`internal`, same package) — moved out of `ConversationRow.kt` so both call sites consume one definition.

docs/knowledge/codebase/88.md

@@ -0,0 +1,40 @@
+# #88 — Persist `useWallpaperColors` preference + dynamic `ColorScheme` branching
+
+Adds a third boolean DataStore key (`use_wallpaper_colors`, default `false`) on `AppPreferences` with a `Flow<Boolean>` getter + `suspend` setter, then collects it at the composition root and forwards it into `PyrycodeMobileTheme`'s pre-existing `dynamicColor: Boolean = false` parameter. The theme function's internal SDK gate (`Build.VERSION.SDK_INT >= Build.VERSION_CODES.S`) already falls back to the brand `lightScheme` / `darkScheme` when `dynamicColor = true` is passed on a pre-S device, so no Android-version branching exists at the call site — and `Theme.kt` (the Material Theme Builder export) is intentionally untouched. Invisible-by-default: the only path to flip the new key is the new setter, and the sibling Settings row that will consume it lives in #89.
+
+## Summary
+
+- `AppPreferences.kt` — adds `useWallpaperColors: Flow<Boolean>` + `suspend fun setUseWallpaperColors(enabled: Boolean)` mirroring the existing `pairedServerExists` shape exactly. New `booleanPreferencesKey("use_wallpaper_colors")` companion constant; no new imports (the boolean builder is already imported for `PAIRED_SERVER_EXISTS`).
+- `MainActivity.kt` — second `collectAsStateWithLifecycle(initialValue = false)` collector immediately after the existing `themeMode` collect at the top of `setContent`; theme call becomes `PyrycodeMobileTheme(darkTheme = darkTheme, dynamicColor = useWallpaperColors) { … }`. The `darkTheme` resolution block from #86 is unchanged.
+- `AppPreferencesTest.kt` — two new tests next to the existing five: `useWallpaperColors_defaultsToFalse` and `setUseWallpaperColors_roundTripsBothValues` (single function that walks `false → true → false`, exercising both round-trip and flow-re-emission ACs in one body — the architect's spec called this out as preferable to a duplicate flow-re-emit test).
+
+No changes to `Theme.kt`, `AppModule.kt`, `SettingsScreen.kt`, `SettingsViewModel.kt`, drawables, or `strings.xml`. The 18+ `@Preview` call sites of `PyrycodeMobileTheme(...)` keep working because `dynamicColor` has a `false` default and the new call site passes it as a named argument.
+
+## Files touched
+
+- `app/src/main/java/de/pyryco/mobile/data/preferences/AppPreferences.kt:31-43` — new flow + setter + key constant; placed below `themeMode` (Appearance grouping) and after `THEME_MODE` in the companion (matching the surface order).
+- `app/src/main/java/de/pyryco/mobile/MainActivity.kt:62-70` — new `useWallpaperColors` collector; theme call gains `dynamicColor = useWallpaperColors`.
+- `app/src/test/java/de/pyryco/mobile/data/preferences/AppPreferencesTest.kt:80-96` — two new `@Test` methods.
+
+## Patterns established
+
+- **Reuse `PyrycodeMobileTheme`'s existing parameter rather than thread a pre-resolved `ColorScheme`.** The ticket's AC offered either route ("explicit parameter or composition root computing it before the call"). Picking the boolean parameter that's already on the function preserves the `darkTheme: Boolean` precedent from #86 ([[caller-computes-darkTheme]] in `86.md`) and avoids changing a signature with 18+ `@Preview` callers. The rule generalises: if the theme primitive already accepts a boolean for the dimension you're wiring, extend the call site, not the signature. Passing a `ColorScheme` directly would invert the encapsulation `Theme.kt` was designed around and force every preview to compute its own scheme.
+- **Sibling boolean-flow collectors stack at the same `setContent` scope.** `MainActivity.setContent` now hosts two activity-level `collectAsStateWithLifecycle` calls back-to-back — `themeMode` (#86) and `useWallpaperColors` (#88) — both feeding one `PyrycodeMobileTheme(...)` invocation. Future cross-cutting theme-or-locale prefs that need to recompose the entire app should follow this shape: keep the collectors siblings at the `setContent` top, not nested in a child composable. Drilling them through `PyryNavHost` would route globally-relevant state through navigation boilerplate.
+- **`initialValue = false` matches the cold-flow default, no flash on first frame.** Same shape `86.md` established for `initialValue = ThemeMode.SYSTEM` — pick the value the cold flow would emit first on a fresh DataStore. The general rule is now codified in [App preferences#Usage](../features/app-preferences.md) and applies to every future `collectAsStateWithLifecycle(initialValue = ...)` site here.
+- **One round-trip test covers both "round-trip" and "flow re-emits" ACs.** The architect's spec noted that a separate `useWallpaperColors_flowReemitsAfterWrite` test would duplicate work — each `first()` call after a write resubscribes and *cannot* see the new value unless DataStore re-emits, so the round-trip test exercises both contracts. Two near-identical test methods is the noisier shape; one method with `false → true → false` is the simpler one. Apply the same compression to any future boolean preference where the ACs separately call out "round-trip" and "flow re-emits."
+
+## Lessons learned
+
+- **`PyrycodeMobileTheme.dynamicColor` already gates the SDK check internally — don't re-check at the call site.** The architect's spec flagged this, and reading `Theme.kt:275` confirms it: `dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S` is the canonical gate, and `dynamicColor = true` on a pre-S device cleanly falls through to the brand `lightScheme` / `darkScheme`. Wrapping the call site in an extra `if (Build.VERSION.SDK_INT >= S)` would be a redundant defense for a code path the theme primitive already owns. Min SDK 33 means pre-S devices aren't reachable in production anyway, but the gate is correct defense regardless.
+- **Companion-object key ordering is cosmetic — group by surface, not by type.** `THEME_MODE` is a `stringPreferencesKey` and `USE_WALLPAPER_COLORS` is a `booleanPreferencesKey`, but placing `USE_WALLPAPER_COLORS` after `THEME_MODE` (both Appearance-section preferences) reads better than sorting by builder type. The spec called this out as cosmetic; future Appearance-section keys (per-row notification sound profile, default model, default effort — all enumerated in [Settings screen](../features/settings-screen.md)) should land at the end of the section group, not interleaved alphabetically.
+- **`setUseWallpaperColors` is intentionally unused on the main path.** No production caller wires the setter in this slice — #89 will. The lesson: a `suspend` setter without a caller is not dead code when the sibling ticket that consumes it is already filed; trying to "demonstrate the setter" from a debug menu or test-only entry point would be code that ships and then has to be unshipped. The smoke-test verification in the PR description (temporary write from a debug code path on a Pixel 8 emulator API 34) is the right form of "yes, recomposition works" without burdening the production tree.
+
+## Links
+
+- Issue: https://github.com/pyrycode/pyrycode-mobile/issues/88
+- Spec: `docs/specs/architecture/88-use-wallpaper-colors-preference.md`
+- Depends on: #86 ([`./86.md`](./86.md)) — the composition-root collector pattern + `darkTheme: Boolean` precedent this ticket extends one more parameter
+- Sibling ticket (deferred): #89 — visible Material You switch row in Settings → Appearance; consumer-of-record for `setUseWallpaperColors(...)` via the row's `onCheckedChange`
+- Split from: #75 (broader Material You / dynamic-color UX work)
+- Feature docs touched: [App preferences](../features/app-preferences.md)
+- Theme primitive (untouched): `app/src/main/java/de/pyryco/mobile/ui/theme/Theme.kt:264-289` — `PyrycodeMobileTheme(darkTheme: Boolean = …, dynamicColor: Boolean = false, …)`; SDK gate at `Theme.kt:275`