feat: add BiliBili audio source integration

Implement BiliBiliProvider for video-as-audio playback using direct
BiliBili API calls (search, video info, DASH audio URL extraction).
Add QR code login support and cookie persistence. Update FFmpeg to
send Referer header for BiliBili CDN URLs. Extend platform union type
to "netease" | "qq" | "bilibili" across all interfaces. Add -b flag
for chat commands and B站 badge in web UI.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

web/src/components/SongCard.vue

@@ -7,8 +7,8 @@
         <span class="song-name">{{ song.name }}</span>
         <span
           class="platform-badge"
-          :class="song.platform === 'qq' ? 'badge-qq' : 'badge-netease'"
-        >{{ song.platform === 'qq' ? 'QQ' : '网易云' }}</span>
+          :class="song.platform === 'bilibili' ? 'badge-bilibili' : song.platform === 'qq' ? 'badge-qq' : 'badge-netease'"
+        >{{ song.platform === 'bilibili' ? 'B站' : song.platform === 'qq' ? 'QQ' : '网易云' }}</span>
       </div>
       <div class="song-artist">{{ song.artist }}</div>
     </div>
@@ -113,6 +113,11 @@ function formatDuration(seconds: number): string {
   color: #12b76a;
 }
 
+.badge-bilibili {
+  background: rgba(0, 161, 214, 0.15);
+  color: #00a1d6;
+}
+
 .song-artist {
   font-size: 12px;
   color: var(--text-secondary);

web/src/views/Settings.vue

@@ -193,6 +193,75 @@
           <button class="btn-primary btn-save" @click="saveCookie('qq')">保存Cookie</button>
         </div>
       </div>
+      <!-- BiliBili -->
+      <div class="account-card">
+        <div class="account-header">
+          <Icon icon="mdi:video-outline" class="account-icon bilibili-icon" />
+          <div class="account-info">
+            <div class="account-name">哔哩哔哩</div>
+            <div class="account-status" :class="{ logged: bilibiliAuth.loggedIn }">
+              {{ bilibiliAuth.loggedIn ? `已登录: ${bilibiliAuth.nickname}` : '未登录' }}
+            </div>
+          </div>
+        </div>
+
+        <div class="login-methods">
+          <button
+            class="login-btn"
+            :class="{ active: bilibiliLoginMode === 'qr' }"
+            @click="startQrLogin('bilibili')"
+            :disabled="bilibiliQr.loading"
+          >
+            <Icon icon="mdi:qrcode" />
+            扫码登录
+          </button>
+          <button
+            class="login-btn"
+            :class="{ active: bilibiliLoginMode === 'cookie' }"
+            @click="bilibiliLoginMode = 'cookie'"
+          >
+            <Icon icon="mdi:cookie" />
+            Cookie登录
+          </button>
+        </div>
+
+        <!-- QR Code -->
+        <div v-if="bilibiliLoginMode === 'qr'" class="qr-section">
+          <div v-if="bilibiliQr.loading" class="qr-loading">
+            <Icon icon="mdi:loading" class="spin" />
+            生成二维码中...
+          </div>
+          <div v-else-if="bilibiliQr.dataUrl" class="qr-wrap">
+            <img :src="bilibiliQr.dataUrl" class="qr-image" alt="QR Code" />
+            <div class="qr-status" :class="bilibiliQr.status">
+              <template v-if="bilibiliQr.status === 'waiting'">
+                <Icon icon="mdi:cellphone" /> 请使用哔哩哔哩APP扫码
+              </template>
+              <template v-else-if="bilibiliQr.status === 'scanned'">
+                <Icon icon="mdi:check" /> 已扫码，请在手机上确认
+              </template>
+              <template v-else-if="bilibiliQr.status === 'confirmed'">
+                <Icon icon="mdi:check-circle" /> 登录成功!
+              </template>
+              <template v-else-if="bilibiliQr.status === 'expired'">
+                <Icon icon="mdi:refresh" /> 二维码已过期
+                <button class="btn-link" @click="startQrLogin('bilibili')">重新生成</button>
+              </template>
+            </div>
+          </div>
+        </div>
+
+        <!-- Cookie -->
+        <div v-if="bilibiliLoginMode === 'cookie'" class="cookie-section">
+          <textarea
+            v-model="bilibiliCookie"
+            class="textarea"
+            placeholder="粘贴哔哩哔哩Cookie..."
+            rows="3"
+          />
+          <button class="btn-primary btn-save" @click="saveCookie('bilibili')">保存Cookie</button>
+        </div>
+      </div>
     </section>
 
     <!-- Audio Quality -->
@@ -248,6 +317,7 @@ const newBotName = ref('');
 const newBotServer = ref('');
 const neteaseCookie = ref('');
 const qqCookie = ref('');
+const bilibiliCookie = ref('');
 const commandPrefix = ref('!');
 
 // Audio quality
@@ -278,10 +348,12 @@ async function setQuality(q: string) {
 // Login mode: 'qr' | 'cookie' | null
 const neteaseLoginMode = ref<'qr' | 'cookie' | null>(null);
 const qqLoginMode = ref<'qr' | 'cookie' | null>(null);
+const bilibiliLoginMode = ref<'qr' | 'cookie' | null>(null);
 
 // Auth status
 const neteaseAuth = reactive({ loggedIn: false, nickname: '', avatarUrl: '' });
 const qqAuth = reactive({ loggedIn: false, nickname: '', avatarUrl: '' });
+const bilibiliAuth = reactive({ loggedIn: false, nickname: '', avatarUrl: '' });
 
 // QR state
 interface QrState {
@@ -298,19 +370,25 @@ const neteaseQr = reactive<QrState>({
 const qqQr = reactive<QrState>({
   loading: false, dataUrl: '', key: '', status: 'waiting', pollTimer: null,
 });
+const bilibiliQr = reactive<QrState>({
+  loading: false, dataUrl: '', key: '', status: 'waiting', pollTimer: null,
+});
 
 function getQrState(platform: string): QrState {
+  if (platform === 'bilibili') return bilibiliQr;
   return platform === 'netease' ? neteaseQr : qqQr;
 }
 
 async function checkAuthStatus() {
   try {
-    const [nRes, qRes] = await Promise.all([
+    const [nRes, qRes, bRes] = await Promise.all([
       axios.get('/api/auth/status', { params: { platform: 'netease' } }),
       axios.get('/api/auth/status', { params: { platform: 'qq' } }),
+      axios.get('/api/auth/status', { params: { platform: 'bilibili' } }),
     ]);
     Object.assign(neteaseAuth, nRes.data);
     Object.assign(qqAuth, qRes.data);
+    Object.assign(bilibiliAuth, bRes.data);
   } catch {
     // API not ready
   }
@@ -319,6 +397,7 @@ async function checkAuthStatus() {
 async function startQrLogin(platform: string) {
   const qr = getQrState(platform);
   if (platform === 'netease') neteaseLoginMode.value = 'qr';
+  else if (platform === 'bilibili') bilibiliLoginMode.value = 'qr';
   else qqLoginMode.value = 'qr';
 
   // Stop existing poll
@@ -412,7 +491,7 @@ async function toggleBot(botId: string, connected: boolean) {
 }
 
 async function saveCookie(platform: string) {
-  const cookie = platform === 'netease' ? neteaseCookie.value : qqCookie.value;
+  const cookie = platform === 'bilibili' ? bilibiliCookie.value : platform === 'netease' ? neteaseCookie.value : qqCookie.value;
   if (!cookie) return;
   try {
     await axios.post('/api/auth/cookie', { platform, cookie });
@@ -434,6 +513,7 @@ onMounted(() => {
 onUnmounted(() => {
   if (neteaseQr.pollTimer) clearInterval(neteaseQr.pollTimer);
   if (qqQr.pollTimer) clearInterval(qqQr.pollTimer);
+  if (bilibiliQr.pollTimer) clearInterval(bilibiliQr.pollTimer);
 });
 </script>
 
@@ -563,6 +643,10 @@ onUnmounted(() => {
 .account-icon {
   font-size: 28px;
   color: var(--color-primary);
+
+  &.bilibili-icon {
+    color: #00a1d6;
+  }
 }
 
 .account-name {