feat(遊戲化): 新增大廳、附身、時間流、後日談進度等遊戲化系統功能

新增角色大廳（lobby）邀約與通話、附身（possession）、時鐘（clock）抽象、
時間流與睡眠負債、後日談進度、行為選擇與旁觀反應等模組，並補齊對應冒煙
測試（R~V）與單元測試；同步調整 web/mobile 對應頁面與元件。

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/mobile/app/(tabs)/settings.tsx

@@ -1,8 +1,9 @@
-import { useState } from "react";
-import { Pressable, ScrollView, StyleSheet, Text, View } from "react-native";
+import { useEffect, useState } from "react";
+import { Pressable, ScrollView, StyleSheet, Switch, Text, View } from "react-native";
 import * as Device from "expo-device";
 import * as Notifications from "expo-notifications";
 import { fetchHealth, registerPushToken } from "../../lib/api";
+import { isVoiceAutoplayEnabled, setVoiceAutoplayEnabled } from "../../lib/voice-autoplay-settings";
 
 const USER_ID = "seed-user-primary";
 
@@ -13,6 +14,17 @@ export default function SettingsScreen() {
   const [healthStatus, setHealthStatus] = useState<string | null>(null);
   const [healthError, setHealthError] = useState<string | null>(null);
   const [pushStatus, setPushStatus] = useState<string | null>(null);
+  // T20-P3：與 apps/web 的 VoiceAutoplaySection.tsx 對應，關閉後房間畫面回到逐則點擊才播放。
+  const [voiceAutoplay, setVoiceAutoplay] = useState(true);
+
+  useEffect(() => {
+    void isVoiceAutoplayEnabled().then(setVoiceAutoplay);
+  }, []);
+
+  async function handleToggleVoiceAutoplay(next: boolean) {
+    await setVoiceAutoplayEnabled(next);
+    setVoiceAutoplay(next);
+  }
 
   async function checkHealth() {
     setHealthError(null);
@@ -64,6 +76,15 @@ export default function SettingsScreen() {
         </Pressable>
         {pushStatus && <Text style={styles.line}>{pushStatus}</Text>}
       </View>
+
+      <View style={styles.card}>
+        <Text style={styles.cardTitle}>自走語音自動播放</Text>
+        <Text style={styles.line}>開啟後，在房間畫面時角色的新發言會自動依序念出來；關閉則回到逐則點擊才播放。</Text>
+        <View style={styles.switchRow}>
+          <Switch value={voiceAutoplay} onValueChange={(next) => void handleToggleVoiceAutoplay(next)} />
+          <Text style={styles.line}>在房間時自動播放角色語音</Text>
+        </View>
+      </View>
     </ScrollView>
   );
 }
@@ -78,4 +99,5 @@ const styles = StyleSheet.create({
   buttonText: { color: "#fff", fontWeight: "bold" },
   line: { fontSize: 13, color: "#222" },
   error: { color: "#FF7E9D", fontSize: 12 },
+  switchRow: { flexDirection: "row", alignItems: "center", gap: 10 },
 });