music: 加 LLM chat、笔记 tab 化、歌单/标签

chat（右边栏）:
- chat_messages 表 per piece，OpenAI 兼容 /v1/chat/completions stream:true
- backend SSE forward delta，结束时落库 user + assistant
- system prompt 注入曲目 (title/artist/category/notes/lyrics 截 4KB)
- 网关同 mochi/config.yaml: gemma-4-31b-it on 3.135.65.204:8848，token 走 k8s Secret chat-creds
- reqwest client 去掉全局 timeout（chat 流可能跑很久），chord sidecar 调用改 per-request timeout

笔记: 从右 sidebar 移到独立 tab "笔记"

歌单 + tag:
- playlists / playlist_pieces / tags / piece_tags 表，CRUD API
- PATCH piece 接 tags 数组（按名字 upsert）
- list pieces 加 ?tag/?playlist 过滤 + 返回 tags 列表
- 顶 bar filterbar：歌单 + 标签 chip 切换；"+ 新歌单" prompt 创建
- EditView 加 tag 编辑（chip + 自动补全）+ 加入/移除歌单

apps/music/Cargo.toml

@@ -17,3 +17,5 @@ serde = { workspace = true }
 serde_json = { workspace = true }
 rusqlite = { workspace = true }
 reqwest = { workspace = true }
+futures = { workspace = true }
+tokio-stream = { workspace = true }

apps/music/frontend/src/lib/api.js

@@ -8,8 +8,12 @@ async function jsonOrThrow(res) {
   return res.json()
 }
 
-export function listPieces() {
-  return fetch('/api/pieces').then(jsonOrThrow)
+export function listPieces({ tag, playlist } = {}) {
+  const qs = new URLSearchParams()
+  if (tag) qs.set('tag', tag)
+  if (playlist) qs.set('playlist', String(playlist))
+  const q = qs.toString()
+  return fetch('/api/pieces' + (q ? '?' + q : '')).then(jsonOrThrow)
 }
 
 export function getPiece(id) {
@@ -65,3 +69,126 @@ export function chordFetch(pieceId) {
 export function chordStatus(pieceId) {
   return fetch(`/api/pieces/${pieceId}/chord/status`).then(jsonOrThrow)
 }
+
+// ---- chat ----
+
+export function listChat(pieceId) {
+  return fetch(`/api/pieces/${pieceId}/chat`).then(jsonOrThrow)
+}
+
+export function clearChat(pieceId) {
+  return fetch(`/api/pieces/${pieceId}/chat`, { method: 'DELETE' }).then(jsonOrThrow)
+}
+
+/**
+ * stream a chat reply.
+ * @param {number} pieceId
+ * @param {string} message
+ * @param {(delta: string) => void} onDelta
+ * @param {AbortSignal} signal
+ * @returns {Promise<{ok: boolean, error?: string}>}
+ */
+export async function streamChat(pieceId, message, onDelta, signal) {
+  const resp = await fetch(`/api/pieces/${pieceId}/chat`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ message }),
+    signal,
+  })
+  if (!resp.ok) {
+    const text = await resp.text().catch(() => '')
+    return { ok: false, error: text || `${resp.status}` }
+  }
+  const reader = resp.body.getReader()
+  const dec = new TextDecoder()
+  let buf = ''
+  let lastEvent = 'message'
+  let errorMsg = ''
+  while (true) {
+    const { done, value } = await reader.read()
+    if (done) break
+    buf += dec.decode(value, { stream: true })
+    let idx
+    while ((idx = buf.indexOf('\n')) >= 0) {
+      const line = buf.slice(0, idx)
+      buf = buf.slice(idx + 1)
+      // SSE 协议：空行 = event 边界（已在内容中处理）；event:/data: 各自一行
+      if (line.startsWith('event:')) {
+        lastEvent = line.slice(6).trim()
+      } else if (line.startsWith('data:')) {
+        const data = line.slice(5).replace(/^ /, '')
+        if (lastEvent === 'error') {
+          errorMsg = data
+        } else if (lastEvent === 'done') {
+          // 不带 data 也算结束
+        } else {
+          onDelta(data)
+        }
+      } else if (line === '') {
+        lastEvent = 'message'
+      }
+    }
+  }
+  if (errorMsg) return { ok: false, error: errorMsg }
+  return { ok: true }
+}
+
+// ---- tags ----
+
+export function listTags() {
+  return fetch('/api/tags').then(jsonOrThrow)
+}
+
+export function createTag(name) {
+  return fetch('/api/tags', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ name }),
+  }).then(jsonOrThrow)
+}
+
+export function deleteTag(id) {
+  return fetch(`/api/tags/${id}`, { method: 'DELETE' }).then(jsonOrThrow)
+}
+
+// ---- playlists ----
+
+export function listPlaylists() {
+  return fetch('/api/playlists').then(jsonOrThrow)
+}
+
+export function createPlaylist(name, description) {
+  return fetch('/api/playlists', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ name, description: description || null }),
+  }).then(jsonOrThrow)
+}
+
+export function getPlaylist(id) {
+  return fetch(`/api/playlists/${id}`).then(jsonOrThrow)
+}
+
+export function patchPlaylist(id, body) {
+  return fetch(`/api/playlists/${id}`, {
+    method: 'PATCH',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify(body),
+  }).then(jsonOrThrow)
+}
+
+export function deletePlaylist(id) {
+  return fetch(`/api/playlists/${id}`, { method: 'DELETE' }).then(jsonOrThrow)
+}
+
+export function playlistAddPiece(playlistId, pieceId) {
+  return fetch(`/api/playlists/${playlistId}/pieces`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ piece_id: pieceId }),
+  }).then(jsonOrThrow)
+}
+
+export function playlistRemovePiece(playlistId, pieceId) {
+  return fetch(`/api/playlists/${playlistId}/pieces/${pieceId}`, { method: 'DELETE' }).then(jsonOrThrow)
+}

apps/music/frontend/src/views/EditView.vue

@@ -41,6 +41,26 @@
             <span>笔记</span>
             <textarea v-model="form.notes" rows="3" />
           </label>
+          <label class="field">
+            <span>标签</span>
+            <div class="tag-row">
+              <span v-for="t in tags" :key="t" class="tag-chip">
+                #{{ t }}
+                <button class="tag-x" @click="removeTag(t)">×</button>
+              </span>
+              <input
+                v-model="tagInput"
+                @keydown.enter.prevent="addTag"
+                @blur="addTag"
+                list="tag-suggest"
+                class="tag-input"
+                placeholder="输入 + 回车（流行/钢琴/吉他/卡拉OK/英文…）"
+              />
+              <datalist id="tag-suggest">
+                <option v-for="t in allTags" :key="t.id" :value="t.name" />
+              </datalist>
+            </div>
+          </label>
           <div class="actions">
             <button class="btn-primary" :disabled="savingMeta" @click="saveMeta">
               {{ savingMeta ? '保存中…' : '保存基本信息' }}
@@ -49,6 +69,32 @@
           </div>
         </section>
 
+        <section class="block">
+          <h2>歌单</h2>
+          <p v-if="memberPlaylists.length === 0" class="hint-sub">这首歌还没在任何歌单里。</p>
+          <div v-else class="pl-row">
+            <span
+              v-for="plId in memberPlaylists"
+              :key="plId"
+              class="tag-chip"
+            >
+              {{ (playlists.find(x => x.id === plId) || {}).name || ('#' + plId) }}
+              <button class="tag-x" @click="leavePlaylist(plId)">×</button>
+            </span>
+          </div>
+          <div class="join-row">
+            <select v-model="addToPlaylistId">
+              <option value="">— 选歌单 —</option>
+              <option
+                v-for="pl in playlists.filter(p => !memberPlaylists.includes(p.id))"
+                :key="pl.id"
+                :value="pl.id"
+              >{{ pl.name }} ({{ pl.count }})</option>
+            </select>
+            <button class="btn-ghost" :disabled="!addToPlaylistId" @click="joinPlaylist">加入</button>
+          </div>
+        </section>
+
         <section class="block">
           <h2>添加附件</h2>
           <p class="hint-sub">
@@ -119,6 +165,11 @@ import {
   deletePiece,
   uploadAttachments,
   deleteAttachment,
+  listTags,
+  listPlaylists,
+  playlistAddPiece,
+  playlistRemovePiece,
+  getPlaylist,
 } from '../lib/api.js'
 
 const props = defineProps({ id: { type: Number, required: true } })
@@ -138,6 +189,14 @@ const form = reactive({
 const savingMeta = ref(false)
 const savedFlash = ref(false)
 
+const tags = ref([])              // 当前 piece 的 tags 数组
+const allTags = ref([])           // 全局所有 tags（用于 datalist 提示）
+const tagInput = ref('')
+
+const playlists = ref([])         // 全部 playlists
+const memberPlaylists = ref([])   // 当前 piece 在哪些 playlists 里（id 集合）
+const addToPlaylistId = ref('')
+
 const fileInputEl = ref(null)
 const pendingFiles = ref([])
 const uploadRole = ref(null)
@@ -156,6 +215,20 @@ async function load() {
     form.category = p.category || ''
     form.lyrics = p.lyrics || ''
     form.notes = p.notes || ''
+    tags.value = [...(p.tags || [])]
+    // 全局 tag 列表 + 我所属的 playlists
+    const [allT, allPl] = await Promise.all([listTags(), listPlaylists()])
+    allTags.value = allT || []
+    playlists.value = allPl || []
+    // 反查所属：每个 playlist 拿 detail，看 pieces 包含 props.id 否
+    const memberships = await Promise.all(
+      (allPl || []).map(pl =>
+        getPlaylist(pl.id)
+          .then(d => (d.pieces || []).some(x => x.id === props.id) ? pl.id : null)
+          .catch(() => null)
+      )
+    )
+    memberPlaylists.value = memberships.filter(x => x != null)
   } catch (e) {
     loadErr.value = e.message || String(e)
   } finally {
@@ -163,6 +236,39 @@ async function load() {
   }
 }
 
+function addTag() {
+  const v = tagInput.value.trim()
+  if (!v) return
+  if (!tags.value.includes(v)) tags.value.push(v)
+  tagInput.value = ''
+}
+
+function removeTag(t) {
+  tags.value = tags.value.filter(x => x !== t)
+}
+
+async function joinPlaylist() {
+  const pid = parseInt(addToPlaylistId.value)
+  if (!pid) return
+  try {
+    await playlistAddPiece(pid, props.id)
+    addToPlaylistId.value = ''
+    await load()
+  } catch (e) {
+    alert(e.message || String(e))
+  }
+}
+
+async function leavePlaylist(plId) {
+  if (!confirm('从这个歌单移除？')) return
+  try {
+    await playlistRemovePiece(plId, props.id)
+    await load()
+  } catch (e) {
+    alert(e.message || String(e))
+  }
+}
+
 async function saveMeta() {
   savingMeta.value = true
   try {
@@ -172,6 +278,7 @@ async function saveMeta() {
       category: form.category.trim() || null,
       lyrics: form.lyrics || null,
       notes: form.notes || null,
+      tags: tags.value,
     })
     savedFlash.value = true
     setTimeout(() => (savedFlash.value = false), 1500)
@@ -393,4 +500,59 @@ onMounted(load)
 
 .danger-block { background: rgba(239, 68, 68, 0.05); }
 .danger-block .btn-danger { padding: 8px 18px; font-size: 13px; }
+
+.tag-row {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 6px;
+  align-items: center;
+  background: var(--bg-elev);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  padding: 6px 8px;
+}
+.tag-chip {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  background: rgba(192, 132, 252, 0.12);
+  color: var(--accent);
+  border-radius: 12px;
+  padding: 2px 4px 2px 10px;
+  font-size: 12px;
+}
+.tag-x {
+  background: none;
+  color: var(--accent);
+  font-size: 14px;
+  width: 18px;
+  height: 18px;
+  border-radius: 50%;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+}
+.tag-x:hover { background: rgba(192, 132, 252, 0.2); }
+.tag-input {
+  flex: 1;
+  min-width: 200px;
+  background: transparent;
+  border: none;
+  font-size: 13px;
+  color: var(--text);
+  padding: 4px 6px;
+}
+.tag-input:focus { outline: none; }
+
+.pl-row { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 12px; }
+.join-row { display: flex; gap: 8px; align-items: center; }
+.join-row select {
+  background: var(--bg-elev);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  padding: 6px 10px;
+  font-size: 13px;
+  color: var(--text);
+  min-width: 220px;
+}
 </style>

apps/music/frontend/src/views/PlayerView.vue

@@ -12,6 +12,38 @@
       <router-link to="/upload" class="btn-add" title="新增曲目">＋</router-link>
     </header>
 
+    <nav class="filterbar">
+      <span class="fb-label">歌单</span>
+      <button
+        class="chip"
+        :class="{ active: !activePlaylistId }"
+        @click="setPlaylist(null)"
+      >全部</button>
+      <button
+        v-for="pl in playlists"
+        :key="pl.id"
+        class="chip"
+        :class="{ active: activePlaylistId === pl.id }"
+        @click="setPlaylist(pl.id)"
+      >{{ pl.name }}<span class="chip-n">{{ pl.count }}</span></button>
+      <button class="chip new-chip" @click="promptNewPlaylist">＋ 新歌单</button>
+
+      <span class="fb-sep">·</span>
+      <span class="fb-label">标签</span>
+      <button
+        class="chip"
+        :class="{ active: !activeTagName }"
+        @click="setTag(null)"
+      >全部</button>
+      <button
+        v-for="t in tagsList"
+        :key="t.id"
+        class="chip"
+        :class="{ active: activeTagName === t.name }"
+        @click="setTag(t.name)"
+      >{{ t.name }}<span class="chip-n">{{ t.count }}</span></button>
+    </nav>
+
     <div class="main">
       <aside class="sidebar" :class="{ 'has-selected': !!selected }">
         <div class="sort-bar">
@@ -26,7 +58,7 @@
           <p v-if="loading" class="hint">加载中…</p>
           <p v-else-if="loadError" class="hint err">{{ loadError }}</p>
           <p v-else-if="filtered.length === 0" class="hint">
-            空空如也，<router-link to="/upload">先加一首</router-link>。
+            空空如也<span v-if="activePlaylistId || activeTagName">（当前筛选下）</span>。
           </p>
           <div
             v-for="p in filtered"
@@ -40,6 +72,7 @@
               <div class="row-meta">
                 <span v-if="p.artist">{{ p.artist }}</span>
                 <span v-if="p.category" class="cat">{{ p.category }}</span>
+                <span v-for="tg in p.tags" :key="tg" class="tg">#{{ tg }}</span>
               </div>
             </div>
             <div class="badges">
@@ -65,6 +98,9 @@
               <span v-if="selected.play_count">· 播放 {{ selected.play_count }} 次</span>
               <router-link :to="{ name: 'edit', params: { id: selected.id } }" class="edit-link">编辑</router-link>
             </div>
+            <div v-if="selected.tags && selected.tags.length" class="np-tags">
+              <span v-for="tg in selected.tags" :key="tg" class="tg">#{{ tg }}</span>
+            </div>
           </header>
 
           <nav v-if="tabs.length" class="tabs">
@@ -94,7 +130,7 @@
               >{{ line.text }}</div>
             </div>
 
-            <!-- 谱面（chord / numbered / staff） -->
+            <!-- 谱面 -->
             <div v-show="['chord', 'numbered', 'staff'].includes(activeTab)" class="sheet-box">
               <img
                 v-for="att in roleAttachments(activeTab)"
@@ -103,7 +139,6 @@
                 :alt="att.filename"
                 class="sheet-img"
               />
-              <!-- 吉他谱专属：没图时给个自动抓取按钮 -->
               <div
                 v-if="activeTab === 'chord' && roleAttachments('chord').length === 0"
                 class="auto-fetch"
@@ -149,6 +184,20 @@
                 class="video-el"
               />
             </div>
+
+            <!-- 笔记（独立 tab） -->
+            <div v-show="activeTab === 'notes'" class="notes-box">
+              <div class="notes-head">
+                <span>练琴心得 / 难点 / 备注</span>
+                <span v-if="notesSavedFlash" class="saved">已保存</span>
+              </div>
+              <textarea
+                v-model="notesDraft"
+                @input="onNotesInput"
+                class="notes-area"
+                placeholder="自动保存。任何想法都丢这里…"
+              />
+            </div>
           </main>
 
           <footer class="controls">
@@ -181,16 +230,47 @@
         </template>
       </section>
 
-      <aside v-if="selected" class="notes" :class="{ active: notesOpen }">
-        <header @click="notesOpen = !notesOpen">
-          <span>笔记</span>
-          <span v-if="notesSavedFlash" class="saved">已保存</span>
+      <!-- 右侧 LLM chat 边栏 -->
+      <aside v-if="selected" class="chat">
+        <header class="chat-head">
+          <span>麻薯 · {{ selected.title.slice(0, 12) }}</span>
+          <button class="chat-clear" @click="onChatClear" title="清空对话">清空</button>
         </header>
-        <textarea
-          v-model="notesDraft"
-          @input="onNotesInput"
-          placeholder="练琴心得 / chord 备注 / 难点…"
-        />
+        <div ref="chatBodyEl" class="chat-body">
+          <p v-if="chatLoading" class="chat-empty">载入对话…</p>
+          <p v-else-if="chatMessages.length === 0 && !chatStreaming" class="chat-empty">
+            随便聊点啥，比如：<br>
+            「这首歌的副歌为啥用 6m 起？」<br>
+            「我吉他扫弦节奏总不稳怎么办？」
+          </p>
+          <div
+            v-for="(m, i) in chatMessages"
+            :key="i"
+            class="msg"
+            :class="m.role"
+          >
+            <div class="msg-bubble">{{ m.content }}</div>
+          </div>
+          <div v-if="chatStreaming || chatStreamText" class="msg assistant">
+            <div class="msg-bubble">{{ chatStreamText || '…' }}</div>
+          </div>
+          <p v-if="chatError" class="chat-err">{{ chatError }}</p>
+        </div>
+        <div class="chat-input">
+          <textarea
+            v-model="chatDraft"
+            @keydown.enter.exact.prevent="onChatSend"
+            @keydown.enter.shift.exact="$event => null"
+            :disabled="chatStreaming"
+            placeholder="Enter 发送 · Shift+Enter 换行"
+            rows="2"
+          />
+          <button
+            class="chat-send"
+            :disabled="chatStreaming || !chatDraft.trim()"
+            @click="onChatSend"
+          >{{ chatStreaming ? '⏳' : '↑' }}</button>
+        </div>
       </aside>
     </div>
   </div>
@@ -201,12 +281,18 @@ import { ref, computed, onMounted, onBeforeUnmount, watch, nextTick } from 'vue'
 import { useRoute, useRouter } from 'vue-router'
 import {
   listPieces,
+  listPlaylists,
+  listTags,
+  createPlaylist,
   getPiece,
   patchPiece,
   recordPlay,
   attachmentUrl as attUrl,
   chordFetch,
   chordStatus,
+  listChat,
+  clearChat,
+  streamChat,
 } from '../lib/api.js'
 import { parseLrc } from '../lib/lrc.js'
 
@@ -219,6 +305,11 @@ const loadError = ref('')
 const selected = ref(null)
 const selectedId = ref(null)
 
+const playlists = ref([])
+const tagsList = ref([])
+const activePlaylistId = ref(null)
+const activeTagName = ref(null)
+
 const search = ref('')
 const sortMode = ref(localStorage.getItem('music.sort') || 'name')
 const repeatOne = ref(false)
@@ -229,19 +320,28 @@ const playing = ref(false)
 const currentTime = ref(0)
 const duration = ref(0)
 const activeTab = ref('lyrics')
-const notesOpen = ref(false)
 const notesDraft = ref('')
 const notesSavedFlash = ref(false)
 let notesTimer = null
 let randomSeed = Math.random()
 let lastReportedId = null
 
-// chord auto-fetch state
-const chordState = ref('idle') // idle | pending | processing | completed | failed
+// chord
+const chordState = ref('idle')
 const chordError = ref('')
 let chordPollTimer = null
 let chordPollStarted = 0
 
+// chat
+const chatBodyEl = ref(null)
+const chatMessages = ref([])
+const chatLoading = ref(false)
+const chatDraft = ref('')
+const chatStreaming = ref(false)
+const chatStreamText = ref('')
+const chatError = ref('')
+let chatAbort = null
+
 const lyricsLines = computed(() => parseLrc(selected.value?.lyrics || ''))
 
 const activeLyricIdx = computed(() => {
@@ -271,7 +371,6 @@ const tabs = computed(() => {
   if (!selected.value) return []
   const list = []
   if (selected.value.lyrics) list.push({ key: 'lyrics', label: '歌词', count: 0 })
-  // 吉他谱 tab 永远给（没图时显示自动抓取按钮）
   list.push({ key: 'chord', label: '吉他谱', count: roleAttachments('chord').length })
   const num = roleAttachments('numbered').length
   if (num) list.push({ key: 'numbered', label: '简谱', count: num })
@@ -279,6 +378,7 @@ const tabs = computed(() => {
   if (staff) list.push({ key: 'staff', label: '五线谱', count: staff })
   if (pdfAttachments.value.length) list.push({ key: 'pdf', label: '乐谱 PDF', count: pdfAttachments.value.length })
   if (videoAttachments.value.length) list.push({ key: 'video', label: '视频', count: videoAttachments.value.length })
+  list.push({ key: 'notes', label: '笔记', count: 0 })
   return list
 })
 
@@ -287,7 +387,7 @@ const filtered = computed(() => {
   let arr = pieces.value
   if (q) {
     arr = arr.filter(p => {
-      const hay = `${p.title} ${p.artist || ''} ${p.category || ''}`.toLowerCase()
+      const hay = `${p.title} ${p.artist || ''} ${p.category || ''} ${(p.tags || []).join(' ')}`.toLowerCase()
       return hay.includes(q)
     })
   }
@@ -307,8 +407,7 @@ const filtered = computed(() => {
       })
       break
     case 'random': {
-      // stable random per session
-      const seeded = arr.map((p, i) => ({ p, k: hash(p.id, randomSeed) }))
+      const seeded = arr.map(p => ({ p, k: hash(p.id, randomSeed) }))
       seeded.sort((a, b) => a.k - b.k)
       arr = seeded.map(x => x.p)
       break
@@ -320,7 +419,6 @@ const filtered = computed(() => {
 })
 
 function hash(id, seed) {
-  // 小随机 hash，sort key 稳定
   let x = (id ^ Math.floor(seed * 1e9)) >>> 0
   x = (x ^ (x << 13)) >>> 0
   x = (x ^ (x >>> 17)) >>> 0
@@ -337,7 +435,6 @@ function setSort(mode) {
 }
 
 function iconKinds(kinds) {
-  // 显示主要 kind 徽章；'image' / 'audio' / 'video' / 'pdf'
   const order = ['audio', 'video', 'pdf', 'image']
   return order.filter(k => kinds.includes(k))
 }
@@ -350,7 +447,10 @@ async function loadPieces() {
   loading.value = true
   loadError.value = ''
   try {
-    pieces.value = await listPieces()
+    pieces.value = await listPieces({
+      tag: activeTagName.value,
+      playlist: activePlaylistId.value,
+    })
   } catch (e) {
     loadError.value = e.message || String(e)
   } finally {
@@ -358,25 +458,56 @@ async function loadPieces() {
   }
 }
 
+async function loadPlaylists() {
+  try { playlists.value = await listPlaylists() } catch {}
+}
+async function loadTags() {
+  try { tagsList.value = await listTags() } catch {}
+}
+
+async function setPlaylist(id) {
+  activePlaylistId.value = id
+  if (id) activeTagName.value = null
+  await loadPieces()
+}
+async function setTag(name) {
+  activeTagName.value = name
+  if (name) activePlaylistId.value = null
+  await loadPieces()
+}
+
+async function promptNewPlaylist() {
+  const name = prompt('新歌单名（如：我喜欢的 / 儿子在练）')
+  if (!name || !name.trim()) return
+  try {
+    const r = await createPlaylist(name.trim())
+    await loadPlaylists()
+    setPlaylist(r.id)
+  } catch (e) {
+    alert(e.message || String(e))
+  }
+}
+
 async function loadPiece(id) {
   selected.value = null
   notesDraft.value = ''
-  // 切歌时清空 chord state（避免 polling 漂到新曲目）
   stopChordPoll()
   chordState.value = 'idle'
   chordError.value = ''
+  abortChat()
+  chatMessages.value = []
+  chatStreamText.value = ''
+  chatError.value = ''
   if (!id) return
   try {
     const p = await getPiece(id)
     selected.value = p
     notesDraft.value = p.notes || ''
     selectedId.value = p.id
-    // 默认 tab：有歌词进 lyrics，否则进第一个 tab
     const t = tabs.value
     if (!t.find(x => x.key === activeTab.value)) {
       activeTab.value = t[0]?.key || 'lyrics'
     }
-    // 自动开播放（如果有 audio）
     await nextTick()
     const first = audioAttachments.value[0]
     if (first && audioEl.value) {
@@ -387,18 +518,31 @@ async function loadPiece(id) {
       audioEl.value.load()
     }
     lastReportedId = null
+    // 加载 chat 历史
+    loadChat(id)
   } catch (e) {
     loadError.value = e.message || String(e)
   }
 }
 
+async function loadChat(id) {
+  chatLoading.value = true
+  try {
+    const arr = await listChat(id)
+    if (selectedId.value === id) chatMessages.value = arr || []
+  } catch (e) {
+    chatError.value = e.message || String(e)
+  } finally {
+    chatLoading.value = false
+  }
+}
+
 function selectPiece(id) {
   router.push({ name: 'piece', params: { id } })
 }
 
 function attachmentUrl(id) { return attUrl(id) }
 
-// player controls
 function togglePlay() {
   if (!audioEl.value || !audioEl.value.src) return
   if (audioEl.value.paused) audioEl.value.play()
@@ -434,11 +578,9 @@ function seekBar(e) {
 
 function onTimeUpdate(e) {
   currentTime.value = e.target.currentTime
-  // 上报播放（≥10s 时）
   if (selectedId.value && lastReportedId !== selectedId.value && currentTime.value >= 10) {
     lastReportedId = selectedId.value
     recordPlay(selectedId.value).then(d => {
-      // 同步本地 + list
       if (selected.value) selected.value.play_count = d.play_count
       const inList = pieces.value.find(p => p.id === selectedId.value)
       if (inList) {
@@ -447,7 +589,6 @@ function onTimeUpdate(e) {
       }
     }).catch(() => {})
   }
-  // 自动滚歌词
   if (activeTab.value === 'lyrics' && lyricsBoxEl.value) {
     const idx = activeLyricIdx.value
     if (idx >= 0) {
@@ -455,7 +596,6 @@ function onTimeUpdate(e) {
       if (el) el.scrollIntoView({ behavior: 'smooth', block: 'center' })
     }
   }
-  // 持久化最近播放进度
   if (selectedId.value) {
     localStorage.setItem('music.last', JSON.stringify({
       id: selectedId.value,
@@ -493,6 +633,20 @@ function setTab(k) {
   activeTab.value = k
 }
 
+// notes auto-save
+function onNotesInput() {
+  if (!selectedId.value) return
+  if (notesTimer) clearTimeout(notesTimer)
+  notesTimer = setTimeout(async () => {
+    try {
+      await patchPiece(selectedId.value, { notes: notesDraft.value || null })
+      notesSavedFlash.value = true
+      setTimeout(() => (notesSavedFlash.value = false), 1500)
+    } catch {}
+  }, 600)
+}
+
+// chord
 async function startChordFetch() {
   if (!selectedId.value) return
   chordState.value = 'pending'
@@ -500,7 +654,6 @@ async function startChordFetch() {
   try {
     const r = await chordFetch(selectedId.value)
     if (r.status === 'completed') {
-      // 已经有谱（或刚 import）：刷新 piece
       await reloadPiece()
       chordState.value = 'completed'
       return
@@ -517,11 +670,10 @@ async function startChordFetch() {
 
 async function pollChord() {
   if (!selectedId.value) { stopChordPoll(); return }
-  // 90s 超时保护
   if (Date.now() - chordPollStarted > 90_000) {
     stopChordPoll()
     chordState.value = 'failed'
-    chordError.value = '抓取超时（>90s），可能 yopu 限流或 selector 失效'
+    chordError.value = '抓取超时'
     return
   }
   try {
@@ -535,7 +687,6 @@ async function pollChord() {
       stopChordPoll()
     }
   } catch (e) {
-    // 暂时性错误就不立即放弃，下一轮再试
     chordError.value = e.message || String(e)
   }
 }
@@ -551,22 +702,77 @@ async function reloadPiece() {
   if (!selectedId.value) return
   try {
     const fresh = await getPiece(selectedId.value)
-    // 保留正在播的 audio.src 不动
     selected.value = fresh
   } catch {}
 }
 
-// notes auto-save
-function onNotesInput() {
-  if (!selectedId.value) return
-  if (notesTimer) clearTimeout(notesTimer)
-  notesTimer = setTimeout(async () => {
-    try {
-      await patchPiece(selectedId.value, { notes: notesDraft.value || null })
-      notesSavedFlash.value = true
-      setTimeout(() => (notesSavedFlash.value = false), 1500)
-    } catch {}
-  }, 600)
+// chat
+async function onChatSend() {
+  const msg = chatDraft.value.trim()
+  if (!msg || chatStreaming.value || !selectedId.value) return
+  // 乐观追加 user msg（assistant 流完整结束后会从 db 读最终 +1）
+  chatMessages.value = [
+    ...chatMessages.value,
+    { role: 'user', content: msg, id: Date.now() },
+  ]
+  chatDraft.value = ''
+  chatStreamText.value = ''
+  chatError.value = ''
+  chatStreaming.value = true
+  await nextTick(); scrollChatBottom()
+  const ctrl = new AbortController()
+  chatAbort = ctrl
+  const pidAtStart = selectedId.value
+  try {
+    const result = await streamChat(pidAtStart, msg, (delta) => {
+      if (selectedId.value !== pidAtStart) return
+      chatStreamText.value += delta
+      scrollChatBottom()
+    }, ctrl.signal)
+    if (selectedId.value !== pidAtStart) return
+    if (result.ok) {
+      chatMessages.value = [
+        ...chatMessages.value,
+        { role: 'assistant', content: chatStreamText.value, id: Date.now() + 1 },
+      ]
+    } else {
+      chatError.value = result.error || '出错'
+    }
+  } catch (e) {
+    if (e.name !== 'AbortError') chatError.value = e.message || String(e)
+  } finally {
+    chatStreamText.value = ''
+    chatStreaming.value = false
+    chatAbort = null
+    await nextTick(); scrollChatBottom()
+  }
+}
+
+async function onChatClear() {
+  if (!selectedId.value || !confirm('清空这首歌的对话历史？')) return
+  abortChat()
+  try {
+    await clearChat(selectedId.value)
+    chatMessages.value = []
+    chatStreamText.value = ''
+    chatError.value = ''
+  } catch (e) {
+    alert(e.message || String(e))
+  }
+}
+
+function abortChat() {
+  if (chatAbort) {
+    try { chatAbort.abort() } catch {}
+    chatAbort = null
+  }
+  chatStreaming.value = false
+  chatStreamText.value = ''
+}
+
+function scrollChatBottom() {
+  const el = chatBodyEl.value
+  if (el) el.scrollTop = el.scrollHeight
 }
 
 // keyboard
@@ -600,13 +806,12 @@ watch(() => route.params.id, async (idStr) => {
 
 onMounted(async () => {
   document.addEventListener('keydown', onKeyDown)
-  await loadPieces()
+  await Promise.all([loadPieces(), loadPlaylists(), loadTags()])
   const id = route.params.id ? Number(route.params.id) : null
   if (id) {
     selectedId.value = id
     await loadPiece(id)
   } else {
-    // 无路由 id：恢复 last
     try {
       const last = JSON.parse(localStorage.getItem('music.last') || 'null')
       if (last && pieces.value.find(p => p.id === last.id)) {
@@ -620,6 +825,7 @@ onBeforeUnmount(() => {
   document.removeEventListener('keydown', onKeyDown)
   if (notesTimer) clearTimeout(notesTimer)
   stopChordPoll()
+  abortChat()
 })
 </script>
 
@@ -660,10 +866,55 @@ onBeforeUnmount(() => {
   font-size: 22px; font-weight: 600;
   display: inline-flex; align-items: center; justify-content: center;
   text-decoration: none;
-  transition: background 0.15s;
 }
 .topbar .btn-add:hover { background: var(--accent); text-decoration: none; }
 
+.filterbar {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  padding: 8px 20px;
+  background: var(--bg-elev);
+  border-bottom: 1px solid var(--border-soft);
+  flex-wrap: wrap;
+  flex-shrink: 0;
+  font-size: 12px;
+}
+.fb-label {
+  color: var(--text-mute);
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+  font-size: 10px;
+  margin-right: 2px;
+}
+.fb-sep { color: var(--text-mute); margin: 0 4px; }
+.chip {
+  background: var(--bg);
+  border: 1px solid var(--border);
+  color: var(--text-dim);
+  padding: 4px 10px;
+  border-radius: 12px;
+  font-size: 12px;
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  transition: all 0.15s;
+}
+.chip:hover { color: var(--text); }
+.chip.active {
+  background: var(--bg-active);
+  border-color: var(--accent-strong);
+  color: var(--accent);
+}
+.chip-n {
+  font-size: 10px;
+  color: var(--text-mute);
+}
+.new-chip {
+  border-style: dashed;
+  color: var(--text-mute);
+}
+
 .main {
   flex: 1;
   display: flex;
@@ -672,8 +923,8 @@ onBeforeUnmount(() => {
 }
 
 .sidebar {
-  width: 340px;
-  min-width: 280px;
+  width: 320px;
+  min-width: 260px;
   border-right: 1px solid var(--border-soft);
   display: flex;
   flex-direction: column;
@@ -694,7 +945,6 @@ onBeforeUnmount(() => {
   border: 1px solid var(--border);
   background: var(--bg-elev);
   border-right-width: 0;
-  transition: all 0.15s;
 }
 .sort-bar button:first-child { border-radius: 4px 0 0 4px; }
 .sort-bar button:last-child { border-radius: 0 4px 4px 0; border-right-width: 1px; }
@@ -734,6 +984,7 @@ onBeforeUnmount(() => {
   margin-top: 2px;
   display: flex;
   gap: 6px;
+  flex-wrap: wrap;
 }
 .row-meta .cat {
   color: var(--accent-cyan);
@@ -741,6 +992,14 @@ onBeforeUnmount(() => {
   padding: 0 6px;
   border-radius: 8px;
 }
+.tg {
+  color: var(--accent);
+  background: rgba(192, 132, 252, 0.1);
+  padding: 0 6px;
+  border-radius: 8px;
+  font-size: 11px;
+}
+.np-tags { display: flex; gap: 6px; justify-content: center; margin-top: 4px; flex-wrap: wrap; }
 
 .badges {
   display: flex;
@@ -778,7 +1037,7 @@ onBeforeUnmount(() => {
 }
 
 .now-playing {
-  padding: 18px 24px 8px;
+  padding: 16px 24px 6px;
   text-align: center;
   flex-shrink: 0;
 }
@@ -903,10 +1162,8 @@ onBeforeUnmount(() => {
   border-radius: 8px;
   font-size: 14px;
   font-weight: 600;
-  transition: background 0.15s, transform 0.05s;
 }
 .btn-fetch:hover:not(:disabled) { background: var(--accent); }
-.btn-fetch:active:not(:disabled) { transform: scale(0.97); }
 .btn-fetch .spin { display: inline-block; animation: spin-anim 1.5s linear infinite; }
 @keyframes spin-anim { to { transform: rotate(360deg); } }
 
@@ -928,6 +1185,35 @@ onBeforeUnmount(() => {
   border-radius: 8px;
 }
 
+.notes-box {
+  display: flex;
+  flex-direction: column;
+  height: 100%;
+  gap: 8px;
+}
+.notes-head {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  font-size: 12px;
+  color: var(--text-mute);
+  text-transform: uppercase;
+  letter-spacing: 0.05em;
+}
+.notes-head .saved { color: var(--accent-green); }
+.notes-area {
+  flex: 1;
+  min-height: 240px;
+  background: var(--bg-elev);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  padding: 14px 16px;
+  font-size: 14px;
+  line-height: 1.6;
+  resize: vertical;
+}
+.notes-area:focus { border-color: var(--accent-strong); }
+
 .controls {
   flex-shrink: 0;
   background: var(--bg-card);
@@ -950,7 +1236,6 @@ onBeforeUnmount(() => {
   display: inline-flex;
   align-items: center;
   justify-content: center;
-  transition: background 0.15s, color 0.15s;
 }
 .btn-icon:hover { background: rgba(255,255,255,0.06); color: var(--text); }
 .btn-icon.big {
@@ -1006,36 +1291,113 @@ onBeforeUnmount(() => {
   text-align: center;
 }
 
-.notes {
-  width: 260px;
+/* Chat sidebar */
+.chat {
+  width: 320px;
   border-left: 1px solid var(--border-soft);
   background: var(--bg-elev);
   display: none;
   flex-direction: column;
   flex-shrink: 0;
 }
-.notes header {
-  padding: 12px 16px;
+@media (min-width: 1280px) {
+  .chat { display: flex; }
+}
+.chat-head {
+  padding: 10px 14px;
   font-size: 12px;
   color: var(--text-mute);
   border-bottom: 1px solid var(--border-soft);
   display: flex;
   justify-content: space-between;
-  cursor: pointer;
+  align-items: center;
 }
-.notes header .saved { color: var(--accent-green); font-size: 10px; }
-.notes textarea {
+.chat-clear {
+  background: rgba(239, 68, 68, 0.1);
+  color: var(--accent-red);
+  font-size: 11px;
+  padding: 3px 8px;
+  border-radius: 4px;
+}
+.chat-clear:hover { background: rgba(239, 68, 68, 0.2); }
+
+.chat-body {
   flex: 1;
-  padding: 12px 14px;
+  overflow-y: auto;
+  padding: 12px 12px 8px;
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+.chat-empty {
+  color: var(--text-mute);
   font-size: 13px;
-  line-height: 1.6;
+  text-align: center;
+  padding: 30px 8px;
+  line-height: 1.7;
+}
+.chat-err {
+  color: var(--accent-red);
+  font-size: 12px;
+  background: rgba(239, 68, 68, 0.08);
+  padding: 8px 10px;
+  border-radius: 6px;
+}
+.msg {
+  display: flex;
+}
+.msg.user { justify-content: flex-end; }
+.msg.assistant { justify-content: flex-start; }
+.msg-bubble {
+  max-width: 84%;
+  padding: 8px 12px;
+  border-radius: 12px;
+  font-size: 13px;
+  line-height: 1.55;
+  white-space: pre-wrap;
+  word-break: break-word;
+}
+.msg.user .msg-bubble {
+  background: var(--accent-strong);
+  color: #fff;
+  border-bottom-right-radius: 3px;
+}
+.msg.assistant .msg-bubble {
+  background: var(--bg-card);
+  color: var(--text);
+  border-bottom-left-radius: 3px;
+}
+
+.chat-input {
+  border-top: 1px solid var(--border-soft);
+  padding: 10px;
+  display: flex;
+  gap: 8px;
+  align-items: end;
+}
+.chat-input textarea {
+  flex: 1;
+  background: var(--bg);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  padding: 8px 10px;
+  font-size: 13px;
+  line-height: 1.5;
   resize: none;
-  color: var(--text-dim);
+  color: var(--text);
 }
-.notes textarea::placeholder { color: var(--text-mute); }
-@media (min-width: 1200px) {
-  .notes { display: flex; }
+.chat-input textarea:focus { border-color: var(--accent-strong); outline: none; }
+.chat-send {
+  width: 36px;
+  height: 36px;
+  border-radius: 50%;
+  background: var(--accent-strong);
+  color: #fff;
+  font-size: 16px;
+  font-weight: 600;
+  flex-shrink: 0;
 }
+.chat-send:hover:not(:disabled) { background: var(--accent); }
 
 @media (max-width: 768px) {
   .main { flex-direction: column; }

apps/music/k8s/all.yaml

@@ -53,6 +53,15 @@ spec:
               value: /data/blobs
             - name: CHORD_URL
               value: http://localhost:8001
+            - name: CHAT_GATEWAY
+              value: http://3.135.65.204:8848/v1
+            - name: CHAT_MODEL
+              value: gemma-4-31b-it
+            - name: CHAT_TOKEN
+              valueFrom:
+                secretKeyRef:
+                  name: chat-creds
+                  key: token
           readinessProbe:
             httpGet:
               path: /healthz

apps/music/src/main.rs

@@ -20,10 +20,15 @@ use axum::{
     body::Body,
     extract::{DefaultBodyLimit, Multipart, Path, Query, Request, State},
     http::{header, StatusCode},
-    response::{IntoResponse, Json as JsonResp, Response},
-    routing::{get, post},
+    response::{
+        sse::{Event, Sse},
+        IntoResponse, Json as JsonResp, Response,
+    },
+    routing::{delete, get, post},
     Router,
 };
+use futures::Stream;
+use std::convert::Infallible;
 use rusqlite::{params, Connection, OptionalExtension};
 use serde::{Deserialize, Serialize};
 use serde_json::{json, Value};
@@ -40,6 +45,10 @@ struct AppState {
     /// 同 pod 的 chord-fetcher sidecar root（默认 http://localhost:8001）。
     chord_url: String,
     http: reqwest::Client,
+    /// LLM 网关（OpenAI 兼容 /v1）—— 同 mochi/config.yaml。
+    chat_gateway: String,
+    chat_token: String,
+    chat_model: String,
 }
 
 #[tokio::main]
@@ -80,15 +89,62 @@ async fn main() -> std::io::Result<()> {
             created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
             FOREIGN KEY (piece_id) REFERENCES pieces(id) ON DELETE CASCADE
          );
-         CREATE INDEX IF NOT EXISTS idx_att_piece ON attachments(piece_id);",
+         CREATE INDEX IF NOT EXISTS idx_att_piece ON attachments(piece_id);
+
+         CREATE TABLE IF NOT EXISTS chat_messages (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            piece_id INTEGER NOT NULL,
+            role TEXT NOT NULL,
+            content TEXT NOT NULL,
+            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+            FOREIGN KEY (piece_id) REFERENCES pieces(id) ON DELETE CASCADE
+         );
+         CREATE INDEX IF NOT EXISTS idx_chat_piece ON chat_messages(piece_id);
+
+         CREATE TABLE IF NOT EXISTS tags (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            name TEXT NOT NULL UNIQUE,
+            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+         );
+         CREATE TABLE IF NOT EXISTS piece_tags (
+            piece_id INTEGER NOT NULL,
+            tag_id INTEGER NOT NULL,
+            PRIMARY KEY (piece_id, tag_id),
+            FOREIGN KEY (piece_id) REFERENCES pieces(id) ON DELETE CASCADE,
+            FOREIGN KEY (tag_id) REFERENCES tags(id) ON DELETE CASCADE
+         );
+         CREATE INDEX IF NOT EXISTS idx_pt_tag ON piece_tags(tag_id);
+
+         CREATE TABLE IF NOT EXISTS playlists (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            name TEXT NOT NULL,
+            description TEXT,
+            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+         );
+         CREATE TABLE IF NOT EXISTS playlist_pieces (
+            playlist_id INTEGER NOT NULL,
+            piece_id INTEGER NOT NULL,
+            sort_order INTEGER NOT NULL DEFAULT 0,
+            added_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+            PRIMARY KEY (playlist_id, piece_id),
+            FOREIGN KEY (playlist_id) REFERENCES playlists(id) ON DELETE CASCADE,
+            FOREIGN KEY (piece_id) REFERENCES pieces(id) ON DELETE CASCADE
+         );
+         CREATE INDEX IF NOT EXISTS idx_pp_piece ON playlist_pieces(piece_id);",
     )
     .expect("init schema");
     tracing::info!(%db_path, blobs = %blobs_dir.display(), "music ready");
 
     let chord_url =
         std::env::var("CHORD_URL").unwrap_or_else(|_| "http://localhost:8001".into());
+    let chat_gateway =
+        std::env::var("CHAT_GATEWAY").unwrap_or_else(|_| "http://3.135.65.204:8848/v1".into());
+    let chat_token = std::env::var("CHAT_TOKEN").unwrap_or_default();
+    let chat_model =
+        std::env::var("CHAT_MODEL").unwrap_or_else(|_| "gemma-4-31b-it".into());
+    // 关键：reqwest 默认 timeout 不要给 chat 用 —— chat stream 必须能跑很久。
+    // 对 chord sidecar 的小请求另外用 .timeout() per-request。
     let http = reqwest::Client::builder()
-        .timeout(std::time::Duration::from_secs(15))
         .build()
         .expect("build reqwest client");
 
@@ -97,6 +153,9 @@ async fn main() -> std::io::Result<()> {
         blobs_dir,
         chord_url,
         http,
+        chat_gateway,
+        chat_token,
+        chat_model,
     };
 
     let api = Router::new()
@@ -108,6 +167,10 @@ async fn main() -> std::io::Result<()> {
         .route("/pieces/:id/play", post(record_play))
         .route("/pieces/:id/chord/fetch", post(chord_fetch))
         .route("/pieces/:id/chord/status", get(chord_status))
+        .route(
+            "/pieces/:id/chat",
+            get(list_chat).post(post_chat).delete(clear_chat),
+        )
         .route(
             "/pieces/:id/attachments",
             post(upload_attachments).layer(DefaultBodyLimit::max(REQUEST_BYTES)),
@@ -116,6 +179,18 @@ async fn main() -> std::io::Result<()> {
             "/attachments/:id",
             get(get_attachment).delete(delete_attachment),
         )
+        .route("/tags", get(list_tags).post(create_tag))
+        .route("/tags/:id", delete(delete_tag))
+        .route("/playlists", get(list_playlists).post(create_playlist))
+        .route(
+            "/playlists/:id",
+            get(get_playlist).patch(patch_playlist).delete(delete_playlist),
+        )
+        .route("/playlists/:id/pieces", post(playlist_add_piece))
+        .route(
+            "/playlists/:id/pieces/:piece_id",
+            delete(playlist_remove_piece),
+        )
         .with_state(state);
 
     let app = cube_core::base(dist).nest("/api", api);
@@ -134,6 +209,7 @@ struct PieceSummary {
     last_played_at: Option<String>,
     attachments: i64,
     kinds: Vec<String>,
+    tags: Vec<String>,
     has_lyrics: bool,
     created_at: String,
 }
@@ -150,6 +226,7 @@ struct PieceDetail {
     last_played_at: Option<String>,
     created_at: String,
     attachments: Vec<Attachment>,
+    tags: Vec<String>,
 }
 
 #[derive(Serialize)]
@@ -185,33 +262,74 @@ struct PatchPiece {
     category: Option<Option<String>>,
     notes: Option<Option<String>>,
     lyrics: Option<Option<String>>,
+    /// 整体 replace；空数组等于清空
+    tags: Option<Vec<String>>,
     /// admin / import 用：直接写 play_count（mvp 无认证）
     play_count: Option<i64>,
 }
 
+#[derive(Deserialize, Default)]
+struct ListPiecesQuery {
+    tag: Option<String>,
+    playlist: Option<i64>,
+}
+
 // ---------- handlers: pieces ----------
 
-async fn list_pieces(State(s): State<AppState>) -> Result<JsonResp<Value>, AppError> {
+async fn list_pieces(
+    State(s): State<AppState>,
+    Query(q): Query<ListPiecesQuery>,
+) -> Result<JsonResp<Value>, AppError> {
     let conn = s.db.lock().unwrap();
-    let mut stmt = conn.prepare(
+    // 构造可选 filter 条件。每行 join 一次拿到 piece，subquery 单独算 attachments / tags
+    let (filter_join, filter_where, bind): (&str, &str, Vec<rusqlite::types::Value>) =
+        if let Some(t) = q.tag.as_deref().filter(|s| !s.is_empty()) {
+            (
+                "JOIN piece_tags pt ON pt.piece_id = p.id JOIN tags ft ON ft.id = pt.tag_id",
+                "WHERE ft.name = ?1",
+                vec![t.to_string().into()],
+            )
+        } else if let Some(pid) = q.playlist {
+            (
+                "JOIN playlist_pieces pp ON pp.piece_id = p.id",
+                "WHERE pp.playlist_id = ?1",
+                vec![pid.into()],
+            )
+        } else {
+            ("", "", vec![])
+        };
+    let sql = format!(
         "SELECT p.id, p.title, p.artist, p.category,
                 p.play_count, p.last_played_at, p.created_at,
-                COUNT(a.id) AS att_count,
-                COALESCE(GROUP_CONCAT(DISTINCT a.kind), '') AS kinds,
-                CASE WHEN p.lyrics IS NOT NULL AND length(p.lyrics) > 0 THEN 1 ELSE 0 END AS has_lyrics
+                (SELECT COUNT(*) FROM attachments a WHERE a.piece_id = p.id) AS att_count,
+                COALESCE((SELECT GROUP_CONCAT(DISTINCT a.kind)
+                          FROM attachments a WHERE a.piece_id = p.id), '') AS kinds,
+                CASE WHEN p.lyrics IS NOT NULL AND length(p.lyrics) > 0 THEN 1 ELSE 0 END AS has_lyrics,
+                COALESCE((SELECT GROUP_CONCAT(t.name, char(9))
+                          FROM piece_tags pt2 JOIN tags t ON t.id = pt2.tag_id
+                          WHERE pt2.piece_id = p.id), '') AS tags
          FROM pieces p
-         LEFT JOIN attachments a ON a.piece_id = p.id
+         {filter_join}
+         {filter_where}
          GROUP BY p.id
-         ORDER BY p.title COLLATE NOCASE ASC, p.id ASC",
-    )?;
+         ORDER BY p.title COLLATE NOCASE ASC, p.id ASC"
+    );
+    let mut stmt = conn.prepare(&sql)?;
+    let bind_refs: Vec<&dyn rusqlite::ToSql> = bind.iter().map(|v| v as &dyn rusqlite::ToSql).collect();
     let rows = stmt
-        .query_map([], |r| {
+        .query_map(bind_refs.as_slice(), |r| {
             let kinds_csv: String = r.get(8)?;
             let kinds = if kinds_csv.is_empty() {
                 Vec::new()
             } else {
                 kinds_csv.split(',').map(|x| x.to_string()).collect()
             };
+            let tags_raw: String = r.get(10)?;
+            let tags = if tags_raw.is_empty() {
+                Vec::new()
+            } else {
+                tags_raw.split('\t').map(|x| x.to_string()).collect()
+            };
             let has_lyrics: i64 = r.get(9)?;
             Ok(PieceSummary {
                 id: r.get(0)?,
@@ -223,6 +341,7 @@ async fn list_pieces(State(s): State<AppState>) -> Result<JsonResp<Value>, AppEr
                 created_at: r.get(6)?,
                 attachments: r.get(7)?,
                 kinds,
+                tags,
                 has_lyrics: has_lyrics != 0,
             })
         })?
@@ -312,6 +431,14 @@ async fn get_piece(
         })?
         .collect::<Result<Vec<_>, _>>()?;
 
+    let mut tag_stmt = conn.prepare(
+        "SELECT t.name FROM piece_tags pt JOIN tags t ON t.id = pt.tag_id
+         WHERE pt.piece_id = ?1 ORDER BY t.name COLLATE NOCASE",
+    )?;
+    let tags: Vec<String> = tag_stmt
+        .query_map(params![id], |r| r.get::<_, String>(0))?
+        .collect::<Result<Vec<_>, _>>()?;
+
     Ok(JsonResp(PieceDetail {
         id,
         title,
@@ -323,6 +450,7 @@ async fn get_piece(
         last_played_at,
         created_at,
         attachments,
+        tags,
     }))
 }
 
@@ -383,6 +511,23 @@ async fn patch_piece(
             params![pc, id],
         )?;
     }
+    if let Some(tags) = body.tags {
+        conn.execute(
+            "DELETE FROM piece_tags WHERE piece_id = ?1",
+            params![id],
+        )?;
+        for name in tags {
+            let trimmed = name.trim();
+            if trimmed.is_empty() {
+                continue;
+            }
+            let tag_id = upsert_tag(&conn, trimmed)?;
+            conn.execute(
+                "INSERT OR IGNORE INTO piece_tags (piece_id, tag_id) VALUES (?1, ?2)",
+                params![id, tag_id],
+            )?;
+        }
+    }
     Ok(JsonResp(json!({ "ok": true })))
 }
 
@@ -431,6 +576,511 @@ async fn delete_piece(
     Ok(JsonResp(json!({ "ok": true })))
 }
 
+// ---------- handlers: chat ----------
+
+#[derive(Serialize)]
+struct ChatMessage {
+    id: i64,
+    role: String,
+    content: String,
+    created_at: String,
+}
+
+#[derive(Deserialize)]
+struct PostChat {
+    message: String,
+}
+
+async fn list_chat(
+    State(s): State<AppState>,
+    Path(piece_id): Path<i64>,
+) -> Result<JsonResp<Value>, AppError> {
+    let conn = s.db.lock().unwrap();
+    let mut stmt = conn.prepare(
+        "SELECT id, role, content, created_at FROM chat_messages
+         WHERE piece_id = ?1 ORDER BY id ASC",
+    )?;
+    let rows = stmt
+        .query_map(params![piece_id], |r| {
+            Ok(ChatMessage {
+                id: r.get(0)?,
+                role: r.get(1)?,
+                content: r.get(2)?,
+                created_at: r.get(3)?,
+            })
+        })?
+        .collect::<Result<Vec<_>, _>>()?;
+    Ok(JsonResp(json!(rows)))
+}
+
+async fn clear_chat(
+    State(s): State<AppState>,
+    Path(piece_id): Path<i64>,
+) -> Result<JsonResp<Value>, AppError> {
+    let conn = s.db.lock().unwrap();
+    conn.execute(
+        "DELETE FROM chat_messages WHERE piece_id = ?1",
+        params![piece_id],
+    )?;
+    Ok(JsonResp(json!({ "ok": true })))
+}
+
+/// `POST /api/pieces/:id/chat` — body {"message": "..."}，返回 SSE 流
+/// 每个 event data 是文本片段（assistant delta content）。结束时 emit 一个 `done` event。
+async fn post_chat(
+    State(s): State<AppState>,
+    Path(piece_id): Path<i64>,
+    JsonResp(body): JsonResp<PostChat>,
+) -> Result<Sse<impl Stream<Item = Result<Event, Infallible>>>, AppError> {
+    let user_msg = body.message.trim().to_string();
+    if user_msg.is_empty() {
+        return Err(AppError::bad_request("message required"));
+    }
+    if s.chat_token.is_empty() {
+        return Err(AppError::bad_request("CHAT_TOKEN not configured"));
+    }
+
+    // 拼 messages：system + history + 新 user
+    let (system_prompt, history) = build_chat_context(&s, piece_id)?;
+
+    let mut openai_messages: Vec<Value> = Vec::new();
+    if !system_prompt.is_empty() {
+        openai_messages.push(json!({ "role": "system", "content": system_prompt }));
+    }
+    for m in &history {
+        openai_messages.push(json!({ "role": m.role, "content": m.content }));
+    }
+    openai_messages.push(json!({ "role": "user", "content": user_msg }));
+
+    let payload = json!({
+        "model": s.chat_model,
+        "messages": openai_messages,
+        "stream": true,
+    });
+
+    let url = format!("{}/chat/completions", s.chat_gateway.trim_end_matches('/'));
+    let req = s
+        .http
+        .post(&url)
+        .bearer_auth(&s.chat_token)
+        .json(&payload);
+
+    // 先存用户消息（不等 LLM 完）
+    {
+        let conn = s.db.lock().unwrap();
+        conn.execute(
+            "INSERT INTO chat_messages (piece_id, role, content) VALUES (?1, 'user', ?2)",
+            params![piece_id, &user_msg],
+        )?;
+    }
+
+    let (tx, rx) = tokio::sync::mpsc::channel::<Result<Event, Infallible>>(64);
+    let state_clone = s.clone();
+    tokio::spawn(async move {
+        let mut full = String::new();
+        match req.send().await {
+            Ok(resp) if resp.status().is_success() => {
+                use futures::StreamExt;
+                let mut stream = resp.bytes_stream();
+                let mut buf = String::new();
+                while let Some(chunk) = stream.next().await {
+                    let chunk = match chunk {
+                        Ok(b) => b,
+                        Err(e) => {
+                            let _ = tx
+                                .send(Ok(Event::default()
+                                    .event("error")
+                                    .data(format!("stream: {e}"))))
+                                .await;
+                            break;
+                        }
+                    };
+                    buf.push_str(&String::from_utf8_lossy(&chunk));
+                    while let Some(idx) = buf.find('\n') {
+                        let line = buf[..idx].trim().to_string();
+                        buf.drain(..=idx);
+                        let Some(payload) = line.strip_prefix("data:") else {
+                            continue;
+                        };
+                        let payload = payload.trim();
+                        if payload.is_empty() {
+                            continue;
+                        }
+                        if payload == "[DONE]" {
+                            break;
+                        }
+                        match serde_json::from_str::<Value>(payload) {
+                            Ok(v) => {
+                                if let Some(delta) = v
+                                    .get("choices")
+                                    .and_then(|c| c.get(0))
+                                    .and_then(|c| c.get("delta"))
+                                    .and_then(|d| d.get("content"))
+                                    .and_then(|c| c.as_str())
+                                {
+                                    if !delta.is_empty() {
+                                        full.push_str(delta);
+                                        if tx
+                                            .send(Ok(Event::default().data(delta.to_string())))
+                                            .await
+                                            .is_err()
+                                        {
+                                            // client gone
+                                            return;
+                                        }
+                                    }
+                                }
+                            }
+                            Err(e) => {
+                                tracing::warn!(error = %e, raw = %payload, "chat: bad delta json");
+                            }
+                        }
+                    }
+                }
+            }
+            Ok(resp) => {
+                let st = resp.status();
+                let body = resp.text().await.unwrap_or_default();
+                let _ = tx
+                    .send(Ok(Event::default()
+                        .event("error")
+                        .data(format!("gateway {st}: {body}"))))
+                    .await;
+            }
+            Err(e) => {
+                let _ = tx
+                    .send(Ok(Event::default()
+                        .event("error")
+                        .data(format!("connect: {e}"))))
+                    .await;
+            }
+        }
+        // 持久化 assistant
+        if !full.is_empty() {
+            let conn = state_clone.db.lock().unwrap();
+            let _ = conn.execute(
+                "INSERT INTO chat_messages (piece_id, role, content) VALUES (?1, 'assistant', ?2)",
+                params![piece_id, &full],
+            );
+        }
+        let _ = tx.send(Ok(Event::default().event("done").data(""))).await;
+    });
+
+    Ok(Sse::new(tokio_stream::wrappers::ReceiverStream::new(rx))
+        .keep_alive(axum::response::sse::KeepAlive::default()))
+}
+
+fn build_chat_context(
+    s: &AppState,
+    piece_id: i64,
+) -> Result<(String, Vec<ChatMessage>), AppError> {
+    let conn = s.db.lock().unwrap();
+    type Row = (
+        String,
+        Option<String>,
+        Option<String>,
+        Option<String>,
+        Option<String>,
+    );
+    let row: Option<Row> = conn
+        .query_row(
+            "SELECT title, artist, category, lyrics, notes FROM pieces WHERE id = ?1",
+            params![piece_id],
+            |r| {
+                Ok((
+                    r.get(0)?,
+                    r.get(1)?,
+                    r.get(2)?,
+                    r.get(3)?,
+                    r.get(4)?,
+                ))
+            },
+        )
+        .optional()?;
+    let (title, artist, category, lyrics, notes) = row.ok_or(AppError::NotFound)?;
+
+    let mut sys = String::from(
+        "你是麻薯，一个懂音乐、会乐理、爱聊天的助手。用中文回答，简洁直接，必要时用 markdown。\n\n当前曲目：",
+    );
+    sys.push_str(&format!("《{}》", title));
+    if let Some(a) = artist.as_deref().filter(|s| !s.is_empty()) {
+        sys.push_str(&format!(" — {}", a));
+    }
+    if let Some(c) = category.as_deref().filter(|s| !s.is_empty()) {
+        sys.push_str(&format!("（{}）", c));
+    }
+    if let Some(n) = notes.as_deref().filter(|s| !s.is_empty()) {
+        sys.push_str(&format!("\n用户笔记：{}", n));
+    }
+    if let Some(l) = lyrics.as_deref().filter(|s| !s.is_empty()) {
+        // LRC 太长会爆 prompt，截到 4KB
+        let trimmed = if l.len() > 4096 { &l[..4096] } else { l };
+        sys.push_str(&format!("\n歌词（截断到 4KB）：\n{}", trimmed));
+    }
+
+    let mut stmt = conn.prepare(
+        "SELECT id, role, content, created_at FROM chat_messages
+         WHERE piece_id = ?1 ORDER BY id ASC",
+    )?;
+    let history = stmt
+        .query_map(params![piece_id], |r| {
+            Ok(ChatMessage {
+                id: r.get(0)?,
+                role: r.get(1)?,
+                content: r.get(2)?,
+                created_at: r.get(3)?,
+            })
+        })?
+        .collect::<Result<Vec<_>, _>>()?;
+    Ok((sys, history))
+}
+
+// ---------- handlers: tags ----------
+
+async fn list_tags(State(s): State<AppState>) -> Result<JsonResp<Value>, AppError> {
+    let conn = s.db.lock().unwrap();
+    let mut stmt = conn.prepare(
+        "SELECT t.id, t.name, COUNT(pt.piece_id) AS n
+         FROM tags t LEFT JOIN piece_tags pt ON pt.tag_id = t.id
+         GROUP BY t.id ORDER BY t.name COLLATE NOCASE ASC",
+    )?;
+    let rows: Vec<Value> = stmt
+        .query_map([], |r| {
+            Ok(json!({
+                "id": r.get::<_, i64>(0)?,
+                "name": r.get::<_, String>(1)?,
+                "count": r.get::<_, i64>(2)?,
+            }))
+        })?
+        .collect::<Result<Vec<_>, _>>()?;
+    Ok(JsonResp(json!(rows)))
+}
+
+#[derive(Deserialize)]
+struct CreateTag {
+    name: String,
+}
+
+async fn create_tag(
+    State(s): State<AppState>,
+    JsonResp(body): JsonResp<CreateTag>,
+) -> Result<JsonResp<Value>, AppError> {
+    let name = body.name.trim();
+    if name.is_empty() {
+        return Err(AppError::bad_request("name required"));
+    }
+    let conn = s.db.lock().unwrap();
+    let id = upsert_tag(&conn, name)?;
+    Ok(JsonResp(json!({ "id": id, "name": name })))
+}
+
+fn upsert_tag(conn: &Connection, name: &str) -> Result<i64, rusqlite::Error> {
+    conn.execute(
+        "INSERT INTO tags (name) VALUES (?1) ON CONFLICT(name) DO NOTHING",
+        params![name],
+    )?;
+    conn.query_row("SELECT id FROM tags WHERE name = ?1", params![name], |r| r.get(0))
+}
+
+async fn delete_tag(
+    State(s): State<AppState>,
+    Path(id): Path<i64>,
+) -> Result<JsonResp<Value>, AppError> {
+    let conn = s.db.lock().unwrap();
+    let n = conn.execute("DELETE FROM tags WHERE id = ?1", params![id])?;
+    if n == 0 {
+        return Err(AppError::NotFound);
+    }
+    Ok(JsonResp(json!({ "ok": true })))
+}
+
+// ---------- handlers: playlists ----------
+
+async fn list_playlists(State(s): State<AppState>) -> Result<JsonResp<Value>, AppError> {
+    let conn = s.db.lock().unwrap();
+    let mut stmt = conn.prepare(
+        "SELECT p.id, p.name, p.description, p.created_at,
+                COUNT(pp.piece_id) AS n
+         FROM playlists p LEFT JOIN playlist_pieces pp ON pp.playlist_id = p.id
+         GROUP BY p.id ORDER BY p.created_at DESC, p.id DESC",
+    )?;
+    let rows: Vec<Value> = stmt
+        .query_map([], |r| {
+            Ok(json!({
+                "id": r.get::<_, i64>(0)?,
+                "name": r.get::<_, String>(1)?,
+                "description": r.get::<_, Option<String>>(2)?,
+                "created_at": r.get::<_, String>(3)?,
+                "count": r.get::<_, i64>(4)?,
+            }))
+        })?
+        .collect::<Result<Vec<_>, _>>()?;
+    Ok(JsonResp(json!(rows)))
+}
+
+#[derive(Deserialize)]
+struct CreatePlaylist {
+    name: String,
+    description: Option<String>,
+}
+
+async fn create_playlist(
+    State(s): State<AppState>,
+    JsonResp(body): JsonResp<CreatePlaylist>,
+) -> Result<JsonResp<Value>, AppError> {
+    let name = body.name.trim();
+    if name.is_empty() {
+        return Err(AppError::bad_request("name required"));
+    }
+    let conn = s.db.lock().unwrap();
+    conn.execute(
+        "INSERT INTO playlists (name, description) VALUES (?1, ?2)",
+        params![name, body.description.as_deref()],
+    )?;
+    Ok(JsonResp(json!({ "id": conn.last_insert_rowid() })))
+}
+
+async fn get_playlist(
+    State(s): State<AppState>,
+    Path(id): Path<i64>,
+) -> Result<JsonResp<Value>, AppError> {
+    let conn = s.db.lock().unwrap();
+    let meta: Option<(String, Option<String>, String)> = conn
+        .query_row(
+            "SELECT name, description, created_at FROM playlists WHERE id = ?1",
+            params![id],
+            |r| Ok((r.get(0)?, r.get(1)?, r.get(2)?)),
+        )
+        .optional()?;
+    let (name, description, created_at) = meta.ok_or(AppError::NotFound)?;
+    let mut stmt = conn.prepare(
+        "SELECT p.id, p.title, p.artist, p.category, p.play_count, p.last_played_at,
+                p.created_at,
+                (SELECT COUNT(*) FROM attachments a WHERE a.piece_id = p.id) AS att_count,
+                (SELECT COALESCE(GROUP_CONCAT(DISTINCT a.kind), '')
+                 FROM attachments a WHERE a.piece_id = p.id) AS kinds,
+                CASE WHEN p.lyrics IS NOT NULL AND length(p.lyrics) > 0 THEN 1 ELSE 0 END,
+                pp.sort_order
+         FROM playlist_pieces pp JOIN pieces p ON p.id = pp.piece_id
+         WHERE pp.playlist_id = ?1
+         ORDER BY pp.sort_order ASC, pp.added_at ASC",
+    )?;
+    let pieces: Vec<Value> = stmt
+        .query_map(params![id], |r| {
+            let kinds_csv: String = r.get(8)?;
+            let kinds: Vec<&str> = if kinds_csv.is_empty() {
+                Vec::new()
+            } else {
+                kinds_csv.split(',').collect()
+            };
+            let has_lyrics: i64 = r.get(9)?;
+            Ok(json!({
+                "id": r.get::<_, i64>(0)?,
+                "title": r.get::<_, String>(1)?,
+                "artist": r.get::<_, Option<String>>(2)?,
+                "category": r.get::<_, Option<String>>(3)?,
+                "play_count": r.get::<_, i64>(4)?,
+                "last_played_at": r.get::<_, Option<String>>(5)?,
+                "created_at": r.get::<_, String>(6)?,
+                "attachments": r.get::<_, i64>(7)?,
+                "kinds": kinds,
+                "has_lyrics": has_lyrics != 0,
+                "sort_order": r.get::<_, i64>(10)?,
+            }))
+        })?
+        .collect::<Result<Vec<_>, _>>()?;
+    Ok(JsonResp(json!({
+        "id": id,
+        "name": name,
+        "description": description,
+        "created_at": created_at,
+        "pieces": pieces,
+    })))
+}
+
+#[derive(Deserialize)]
+struct PatchPlaylist {
+    name: Option<String>,
+    description: Option<Option<String>>,
+}
+
+async fn patch_playlist(
+    State(s): State<AppState>,
+    Path(id): Path<i64>,
+    JsonResp(body): JsonResp<PatchPlaylist>,
+) -> Result<JsonResp<Value>, AppError> {
+    let conn = s.db.lock().unwrap();
+    let exists: bool = conn
+        .query_row("SELECT 1 FROM playlists WHERE id = ?1", params![id], |_| Ok(true))
+        .optional()?
+        .unwrap_or(false);
+    if !exists {
+        return Err(AppError::NotFound);
+    }
+    if let Some(n) = body.name.as_ref() {
+        let n = n.trim();
+        if n.is_empty() {
+            return Err(AppError::bad_request("name can't be blank"));
+        }
+        conn.execute(
+            "UPDATE playlists SET name = ?1 WHERE id = ?2",
+            params![n, id],
+        )?;
+    }
+    if let Some(d) = body.description {
+        conn.execute(
+            "UPDATE playlists SET description = ?1 WHERE id = ?2",
+            params![d.as_deref(), id],
+        )?;
+    }
+    Ok(JsonResp(json!({ "ok": true })))
+}
+
+async fn delete_playlist(
+    State(s): State<AppState>,
+    Path(id): Path<i64>,
+) -> Result<JsonResp<Value>, AppError> {
+    let conn = s.db.lock().unwrap();
+    let n = conn.execute("DELETE FROM playlists WHERE id = ?1", params![id])?;
+    if n == 0 {
+        return Err(AppError::NotFound);
+    }
+    Ok(JsonResp(json!({ "ok": true })))
+}
+
+#[derive(Deserialize)]
+struct AddPiece {
+    piece_id: i64,
+}
+
+async fn playlist_add_piece(
+    State(s): State<AppState>,
+    Path(id): Path<i64>,
+    JsonResp(body): JsonResp<AddPiece>,
+) -> Result<JsonResp<Value>, AppError> {
+    let conn = s.db.lock().unwrap();
+    conn.execute(
+        "INSERT INTO playlist_pieces (playlist_id, piece_id, sort_order)
+         VALUES (?1, ?2,
+            COALESCE((SELECT MAX(sort_order) FROM playlist_pieces WHERE playlist_id = ?1), 0) + 1)
+         ON CONFLICT(playlist_id, piece_id) DO NOTHING",
+        params![id, body.piece_id],
+    )?;
+    Ok(JsonResp(json!({ "ok": true })))
+}
+
+async fn playlist_remove_piece(
+    State(s): State<AppState>,
+    Path((id, piece_id)): Path<(i64, i64)>,
+) -> Result<JsonResp<Value>, AppError> {
+    let conn = s.db.lock().unwrap();
+    conn.execute(
+        "DELETE FROM playlist_pieces WHERE playlist_id = ?1 AND piece_id = ?2",
+        params![id, piece_id],
+    )?;
+    Ok(JsonResp(json!({ "ok": true })))
+}
+
 // ---------- handlers: chord auto-fetch ----------
 
 /// `POST /api/pieces/:id/chord/fetch` — 触发 sidecar 抓取 yopu 和弦谱。
@@ -452,6 +1102,7 @@ async fn chord_fetch(
         .http
         .post(&url)
         .query(&[("piece_id", piece_id.to_string()), ("query", query)])
+        .timeout(std::time::Duration::from_secs(15))
         .send()
         .await
         .map_err(|e| AppError::sidecar(format!("post fetch: {e}")))?;
@@ -481,6 +1132,7 @@ async fn chord_status(
     let resp = s
         .http
         .get(&url)
+        .timeout(std::time::Duration::from_secs(10))
         .send()
         .await
         .map_err(|e| AppError::sidecar(format!("get status: {e}")))?;
@@ -504,6 +1156,7 @@ async fn chord_status(
         let _ = s
             .http
             .delete(format!("{}/state/{}", s.chord_url, piece_id))
+            .timeout(std::time::Duration::from_secs(5))
             .send()
             .await;
         return Ok(JsonResp(json!({