feat(settings): C 起步——App 设置页（主题/旁白/思维链默认展开/关于）

新增 AppSettings（DataStore）与 LocalAppPrefs；CyreneRoot 按偏好决定 Miuix 主题模式并下发偏好；设置页从侧边栏进入，返回回聊天。旁白开关与思维链默认展开已接入渲染层。

app/src/main/kotlin/top/yeij/cyrene/app/AppContainer.kt

@@ -3,6 +3,7 @@ package top.yeij.cyrene.app
 import android.content.Context
 import top.yeij.cyrene.core.auth.AuthManager
 import top.yeij.cyrene.core.auth.SessionStore
+import top.yeij.cyrene.core.prefs.AppSettings
 import top.yeij.cyrene.core.prefs.SessionPreferences
 import top.yeij.cyrene.data.api.ApiClientFactory
 import top.yeij.cyrene.data.api.SessionsApi
@@ -15,6 +16,7 @@ class AppContainer(context: Context) {
 
     val sessionStore: SessionStore = SessionStore(context.applicationContext)
     val sessionPreferences: SessionPreferences = SessionPreferences(context.applicationContext)
+    val appSettings: AppSettings = AppSettings(context.applicationContext)
     val authManager: AuthManager = AuthManager(sessionStore)
 
     private var cachedBaseUrl: String? = null

app/src/main/kotlin/top/yeij/cyrene/app/CyreneRoot.kt

@@ -0,0 +1,31 @@
+package top.yeij.cyrene.app
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import top.yeij.cyrene.core.prefs.AppPrefs
+import top.yeij.cyrene.core.prefs.LocalAppPrefs
+import top.yeij.cyrene.core.prefs.ThemeMode
+import top.yeij.cyrene.core.theme.CyreneTheme
+import top.yukonga.miuix.kmp.theme.ColorSchemeMode
+
+/**
+ * 应用根：读 App 偏好 → 决定 Miuix 主题模式 → 通过 [LocalAppPrefs] 下发给渲染层。
+ */
+@Composable
+fun CyreneRoot(container: AppContainer) {
+    val prefs by container.appSettings.data.collectAsState(initial = AppPrefs())
+
+    CompositionLocalProvider(LocalAppPrefs provides prefs) {
+        CyreneTheme(mode = prefs.themeMode.toColorSchemeMode()) {
+            CyreneApp(container)
+        }
+    }
+}
+
+private fun ThemeMode.toColorSchemeMode(): ColorSchemeMode = when (this) {
+    ThemeMode.System -> ColorSchemeMode.System
+    ThemeMode.Light -> ColorSchemeMode.Light
+    ThemeMode.Dark -> ColorSchemeMode.Dark
+}

app/src/main/kotlin/top/yeij/cyrene/app/MainActivity.kt

@@ -4,17 +4,13 @@ import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
-import top.yeij.cyrene.core.theme.CyreneTheme
-
 class MainActivity : ComponentActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         enableEdgeToEdge()
         super.onCreate(savedInstanceState)
         val container = (application as CyreneApplication).container
         setContent {
-            CyreneTheme {
-                CyreneApp(container)
-            }
+            CyreneRoot(container)
         }
     }
 }

app/src/main/kotlin/top/yeij/cyrene/core/prefs/AppSettings.kt

@@ -0,0 +1,69 @@
+package top.yeij.cyrene.core.prefs
+
+import android.content.Context
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.datastore.core.DataStore
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.booleanPreferencesKey
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.stringPreferencesKey
+import androidx.datastore.preferences.preferencesDataStore
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+
+private val Context.appDataStore: DataStore<Preferences> by preferencesDataStore("cyrene_app")
+
+enum class ThemeMode { System, Light, Dark }
+
+/**
+ * App 级偏好（非机密）。
+ *
+ * @param themeMode 主题深浅
+ * @param showNarration 是否显示 `<action>` / `<narration>` 旁白
+ * @param thinkingExpanded 思维链卡片默认是否展开
+ */
+data class AppPrefs(
+    val themeMode: ThemeMode = ThemeMode.System,
+    val showNarration: Boolean = true,
+    val thinkingExpanded: Boolean = true,
+)
+
+/** 全局注入 App 偏好，供聊天渲染等深层组件读取。 */
+val LocalAppPrefs = staticCompositionLocalOf { AppPrefs() }
+
+class AppSettings(context: Context) {
+
+    private val store: DataStore<Preferences> = context.applicationContext.appDataStore
+
+    val data: Flow<AppPrefs> = store.data.map { prefs ->
+        AppPrefs(
+            themeMode = prefs[KEY_THEME_MODE].toThemeMode(),
+            showNarration = prefs[KEY_SHOW_NARRATION] ?: true,
+            thinkingExpanded = prefs[KEY_THINKING_EXPANDED] ?: true,
+        )
+    }
+
+    suspend fun setThemeMode(mode: ThemeMode) {
+        store.edit { it[KEY_THEME_MODE] = mode.name }
+    }
+
+    suspend fun setShowNarration(enabled: Boolean) {
+        store.edit { it[KEY_SHOW_NARRATION] = enabled }
+    }
+
+    suspend fun setThinkingExpanded(enabled: Boolean) {
+        store.edit { it[KEY_THINKING_EXPANDED] = enabled }
+    }
+
+    private fun String?.toThemeMode(): ThemeMode = when (this) {
+        ThemeMode.Light.name -> ThemeMode.Light
+        ThemeMode.Dark.name -> ThemeMode.Dark
+        else -> ThemeMode.System
+    }
+
+    private companion object {
+        val KEY_THEME_MODE = stringPreferencesKey("theme_mode")
+        val KEY_SHOW_NARRATION = booleanPreferencesKey("show_narration")
+        val KEY_THINKING_EXPANDED = booleanPreferencesKey("thinking_expanded")
+    }
+}

app/src/main/kotlin/top/yeij/cyrene/ui/chat/ChatHomeScreen.kt

@@ -13,8 +13,9 @@ import top.yeij.cyrene.app.AppContainer
 import top.yeij.cyrene.ui.common.MiuixDrawer
 import top.yeij.cyrene.ui.sessions.SessionDrawerContent
 import top.yeij.cyrene.ui.sessions.SessionsViewModel
+import top.yeij.cyrene.ui.settings.SettingsScreen
 
-/** 聊天页 + 侧边栏（会话切换）。 */
+/** 聊天页 + 侧边栏（会话切换）+ 设置页。 */
 @Composable
 fun ChatHomeScreen(
     container: AppContainer,
@@ -25,31 +26,39 @@ fun ChatHomeScreen(
     )
     val state by sessionsViewModel.state.collectAsState()
     var drawerOpen by remember { mutableStateOf(false) }
+    var showSettings by remember { mutableStateOf(false) }
 
-    MiuixDrawer(
-        open = drawerOpen,
-        onOpenChange = { drawerOpen = it },
-        content = {
-            ChatScreen(
-                container = container,
-                sessionId = state.activeSessionId,
-                onOpenDrawer = { drawerOpen = true },
-                onLogout = onLogout,
-            )
-        },
-        drawerContent = {
-            SessionDrawerContent(
-                state = state,
-                onSelect = { sessionId ->
-                    sessionsViewModel.select(sessionId)
-                    drawerOpen = false
-                },
-                onCreate = sessionsViewModel::createSession,
-                onDelete = { sessionsViewModel.deleteSession(it.id) },
-                onOpenIot = { /* P2：IoT 页面 */ },
-                onOpenSettings = { /* P2：设置页面 */ },
-                onLogout = onLogout,
-            )
-        },
-    )
+    if (showSettings) {
+        SettingsScreen(container = container, onBack = { showSettings = false })
+    } else {
+        MiuixDrawer(
+            open = drawerOpen,
+            onOpenChange = { drawerOpen = it },
+            content = {
+                ChatScreen(
+                    container = container,
+                    sessionId = state.activeSessionId,
+                    onOpenDrawer = { drawerOpen = true },
+                    onLogout = onLogout,
+                )
+            },
+            drawerContent = {
+                SessionDrawerContent(
+                    state = state,
+                    onSelect = { sessionId ->
+                        sessionsViewModel.select(sessionId)
+                        drawerOpen = false
+                    },
+                    onCreate = sessionsViewModel::createSession,
+                    onDelete = { sessionsViewModel.deleteSession(it.id) },
+                    onOpenIot = { /* P2：IoT 页面 */ },
+                    onOpenSettings = {
+                        drawerOpen = false
+                        showSettings = true
+                    },
+                    onLogout = onLogout,
+                )
+            },
+        )
+    }
 }

app/src/main/kotlin/top/yeij/cyrene/ui/chat/MessageBubble.kt

@@ -18,6 +18,7 @@ import androidx.compose.ui.draw.clip
 import androidx.compose.ui.text.font.FontStyle
 import androidx.compose.ui.unit.dp
 import coil3.compose.AsyncImage
+import top.yeij.cyrene.core.prefs.LocalAppPrefs
 import top.yeij.cyrene.data.api.dto.HistoryMessageDto
 import top.yeij.cyrene.domain.parse.ContentPart
 import top.yeij.cyrene.domain.parse.ParsedBubble
@@ -131,6 +132,7 @@ private fun Bubble(
 /** 旁白/动作：灰斜体小字，依附在气泡上/下。 */
 @Composable
 private fun AnnotationLine(parts: List<ContentPart>) {
+    if (!LocalAppPrefs.current.showNarration) return
     val text = parts.joinToString(" ") { it.text }.trim()
     if (text.isEmpty()) return
     SelectionContainer(modifier = Modifier.padding(horizontal = 8.dp, vertical = 2.dp)) {

app/src/main/kotlin/top/yeij/cyrene/ui/chat/StreamingBlocks.kt

@@ -21,6 +21,7 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
+import top.yeij.cyrene.core.prefs.LocalAppPrefs
 import top.yukonga.miuix.kmp.basic.Text
 import top.yukonga.miuix.kmp.theme.MiuixTheme
 
@@ -35,7 +36,8 @@ fun ThinkingCard(
     modifier: Modifier = Modifier,
 ) {
     if (text.isBlank() && !active) return
-    var expanded by remember { mutableStateOf(active) }
+    val defaultExpanded = LocalAppPrefs.current.thinkingExpanded
+    var expanded by remember { mutableStateOf(active && defaultExpanded) }
     LaunchedEffect(active) {
         if (!active) expanded = false
     }

app/src/main/kotlin/top/yeij/cyrene/ui/settings/SettingsScreen.kt

@@ -0,0 +1,135 @@
+package top.yeij.cyrene.ui.settings
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.launch
+import top.yeij.cyrene.BuildConfig
+import top.yeij.cyrene.app.AppContainer
+import top.yeij.cyrene.core.prefs.AppPrefs
+import top.yeij.cyrene.core.prefs.ThemeMode
+import top.yukonga.miuix.kmp.basic.Scaffold
+import top.yukonga.miuix.kmp.basic.SmallTopAppBar
+import top.yukonga.miuix.kmp.basic.Text
+import top.yukonga.miuix.kmp.basic.TextButton
+import top.yukonga.miuix.kmp.preference.SwitchPreference
+import top.yukonga.miuix.kmp.theme.MiuixTheme
+
+@Composable
+fun SettingsScreen(
+    container: AppContainer,
+    onBack: () -> Unit,
+) {
+    val prefs by container.appSettings.data.collectAsState(initial = AppPrefs())
+    val scope = rememberCoroutineScope()
+    val settings = container.appSettings
+
+    Scaffold(
+        topBar = {
+            SmallTopAppBar(
+                title = "App 设置",
+                navigationIcon = { TextButton("返回", onClick = onBack) },
+            )
+        },
+    ) { padding ->
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(padding)
+                .verticalScroll(rememberScrollState()),
+        ) {
+            SectionTitle("外观")
+            ThemeMode.entries.forEach { mode ->
+                ThemeOption(
+                    label = mode.label(),
+                    selected = prefs.themeMode == mode,
+                    onClick = { scope.launch { settings.setThemeMode(mode) } },
+                )
+            }
+
+            SectionTitle("聊天")
+            SwitchPreference(
+                title = "显示旁白",
+                summary = "以灰斜体小字显示 <action> / <narration>",
+                checked = prefs.showNarration,
+                onCheckedChange = { scope.launch { settings.setShowNarration(it) } },
+            )
+            SwitchPreference(
+                title = "思维链默认展开",
+                summary = "流式期间展开思维链，结束后自动折叠",
+                checked = prefs.thinkingExpanded,
+                onCheckedChange = { scope.launch { settings.setThinkingExpanded(it) } },
+            )
+
+            SectionTitle("关于")
+            Row(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(horizontal = 20.dp, vertical = 14.dp),
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                Text("版本", style = MiuixTheme.textStyles.main, modifier = Modifier.weight(1f))
+                Text(
+                    text = "${BuildConfig.VERSION_NAME} (${BuildConfig.VERSION_CODE})",
+                    style = MiuixTheme.textStyles.footnote1,
+                    color = MiuixTheme.colorScheme.onSurfaceVariantSummary,
+                )
+            }
+            Spacer(Modifier.height(24.dp))
+        }
+    }
+}
+
+@Composable
+private fun SectionTitle(text: String) {
+    Text(
+        text = text,
+        style = MiuixTheme.textStyles.subtitle,
+        color = MiuixTheme.colorScheme.primary,
+        modifier = Modifier.padding(start = 20.dp, top = 20.dp, bottom = 8.dp),
+    )
+}
+
+@Composable
+private fun ThemeOption(
+    label: String,
+    selected: Boolean,
+    onClick: () -> Unit,
+) {
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .clickable(onClick = onClick)
+            .padding(horizontal = 20.dp, vertical = 14.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Text(label, style = MiuixTheme.textStyles.main, modifier = Modifier.weight(1f))
+        if (selected) {
+            Text(
+                text = "✓",
+                style = MiuixTheme.textStyles.main,
+                color = MiuixTheme.colorScheme.primary,
+            )
+        }
+    }
+}
+
+private fun ThemeMode.label(): String = when (this) {
+    ThemeMode.System -> "跟随系统"
+    ThemeMode.Light -> "浅色"
+    ThemeMode.Dark -> "深色"
+}