diff --git a/wwwroot/overlay/pbl_overlay.css b/wwwroot/overlay/pbl_overlay.css
new file mode 100644
index 0000000..1eaaf97
--- /dev/null
+++ b/wwwroot/overlay/pbl_overlay.css
@@ -0,0 +1,122 @@
+/* ============================================================================
+ * pbl_overlay.css —— PBL 覆盖层样式（M9）
+ * 约定：全部选择器以 .pbl- 前缀隔离，绝不覆盖宿主（scense/scense_game）渲染层样式；
+ *      覆盖层为「浮层」定位，pointer-events 精确到子元素，避免遮挡世界渲染交互。
+ * ==========================================================================*/
+
+.pbl-overlay-root { position: relative; }
+
+/* ── 页面壳：数据驱动布局，宿主渲染区由 data-pbl-host 标记 ── */
+[data-pbl-page] { min-height: 100%; }
+
+.pbl-topbar { width: 100%; }
+.pbl-topbar-in {
+  display: flex; align-items: center; gap: 10px;
+  padding: 10px 16px; background: #ffffff; border-bottom: 1px solid #e6e8eb;
+}
+.pbl-title { font-size: 18px; font-weight: 600; color: #1f2329; }
+.pbl-sub { font-size: 12px; color: #8a9099; }
+.pbl-spacer { flex: 1; }
+.pbl-badge {
+  font-size: 12px; padding: 2px 8px; border-radius: 10px;
+  background: #f2f3f5; color: #4e5968; white-space: nowrap;
+}
+.pbl-badge.is-ok { background: #e8f7ee; color: #17864a; }
+.pbl-vbadge { font-size: 12px; padding: 2px 8px; border-radius: 10px; }
+.pbl-vbadge.is-ok { background: #e8f7ee; color: #17864a; }
+.pbl-vbadge.is-warn { background: #fff7e6; color: #a86b00; }
+.pbl-vbadge.is-block { background: #fdecec; color: #b3261e; }
+
+/* ── 导航条（12 页面） ── */
+.pbl-navrail { width: 100%; margin: 8px 0; }
+.pbl-navrail-in { display: flex; flex-wrap: wrap; gap: 8px; }
+.pbl-navitem {
+  font-size: 13px; padding: 6px 12px; border-radius: 4px;
+  background: #f7f8fa; color: #4e5968; text-decoration: none; border: 1px solid transparent;
+}
+.pbl-navitem:hover { border-color: #c9cdd4; }
+.pbl-navitem.is-active { background: #1264e0; color: #fff; }
+
+/* ── 主内容区卡片 ── */
+.pbl-main { width: 100%; }
+.pbl-card {
+  background: #ffffff; border: 1px solid #e6e8eb; border-radius: 6px;
+  padding: 14px 16px; margin: 10px 0;
+}
+.pbl-card h4 { margin: 0 0 8px; font-size: 14px; color: #1f2329; }
+.pbl-goal-q { font-size: 15px; color: #1264e0; margin: 4px 0; }
+.pbl-goal-m, .pbl-dim { font-size: 12px; color: #8a9099; margin: 4px 0; }
+.pbl-steps ol { margin: 0; padding-left: 20px; font-size: 13px; color: #4e5968; }
+.pbl-steps li.is-done { color: #17864a; text-decoration: line-through; }
+.pbl-rubric table { width: 100%; border-collapse: collapse; font-size: 13px; }
+.pbl-rubric th, .pbl-rubric td { border-bottom: 1px solid #f0f1f3; padding: 6px 8px; text-align: left; }
+.pbl-empty { font-size: 12px; color: #a3a8b0; padding: 10px 0; }
+
+/* ── 产出物 / 证据网格 ── */
+.pbl-grid { display: flex; flex-wrap: wrap; gap: 10px; }
+.pbl-tile {
+  display: flex; flex-direction: column; gap: 4px; min-width: 160px;
+  padding: 10px; border: 1px solid #e6e8eb; border-radius: 4px; font-size: 12px;
+}
+.pbl-tile strong { font-size: 13px; color: #1f2329; }
+.pbl-tile em { color: #8a9099; font-style: normal; }
+
+/* ── Agent 对话面板 ── */
+.pbl-chat-log { max-height: 260px; overflow-y: auto; font-size: 13px; }
+.pbl-msg { padding: 6px 8px; border-radius: 4px; margin: 4px 0; background: #f7f8fa; }
+.pbl-msg.is-user { background: #eaf2ff; }
+.pbl-msg.is-agent.is-fallback { background: #fff7e6; }
+.pbl-chat-input { display: flex; gap: 8px; margin-top: 8px; }
+.pbl-chat-input input { flex: 1; padding: 6px 8px; border: 1px solid #c9cdd4; border-radius: 4px; }
+
+/* ── 审批队列 ── */
+.pbl-approvals ul { margin: 0; padding-left: 18px; font-size: 13px; }
+.pbl-approvals li { display: flex; justify-content: space-between; gap: 10px; padding: 4px 0; }
+.pbl-approvals em { color: #a86b00; font-style: normal; }
+
+/* ── HUD 浮层：覆盖在世界渲染区之上，但不阻断渲染层交互 ── */
+.pbl-hud { position: relative; pointer-events: none; }
+.pbl-hud-in { display: flex; flex-direction: column; gap: 8px; padding: 8px 0; }
+.pbl-hud-progress {
+  height: 6px; border-radius: 3px; background: #eceef1; overflow: hidden;
+}
+.pbl-hud-progress span { display: block; height: 100%; width: 0; background: #1264e0; transition: width .2s linear; }
+.pbl-hud-role { font-size: 12px; color: #4e5968; }
+.pbl-hud-acts { display: flex; flex-wrap: wrap; gap: 6px; pointer-events: auto; }
+.pbl-hud-acts button {
+  font-size: 12px; padding: 4px 10px; border-radius: 4px; cursor: pointer;
+  border: 1px solid #c9cdd4; background: #fff; color: #1f2329;
+}
+.pbl-hud-acts button:hover { border-color: #1264e0; color: #1264e0; }
+.pbl-hud-feed { font-size: 12px; color: #4e5968; max-height: 90px; overflow: hidden; }
+.pbl-feedline { padding: 2px 0; border-bottom: 1px dashed #f0f1f3; }
+
+/* ── 降级横幅（9 类错误态）：只提示不阻断，可关闭 ── */
+.pbl-banners {
+  position: sticky; top: 0; z-index: 9000; display: flex; flex-direction: column; gap: 6px;
+}
+.pbl-banner {
+  display: flex; align-items: center; gap: 10px;
+  padding: 8px 12px; border-radius: 4px; font-size: 13px; border: 1px solid transparent;
+}
+.pbl-banner .pbl-b-title { font-weight: 600; }
+.pbl-banner .pbl-b-desc { color: inherit; opacity: .85; }
+.pbl-banner .pbl-b-act { margin-left: auto; cursor: pointer; border: 1px solid currentColor; background: transparent; border-radius: 3px; padding: 2px 8px; font-size: 12px; }
+.pbl-banner.is-warn { background: #fff7e6; color: #a86b00; border-color: #ffe0a3; }
+.pbl-banner.is-error { background: #fdecec; color: #b3261e; border-color: #f7c7c4; }
+.pbl-banner.is-block { background: #f1ecff; color: #4b2fa8; border-color: #ddd2fb; }
+.pbl-banner.is-info { background: #eaf2ff; color: #1264e0; border-color: #cfe0fb; }
+
+/* ── 骨架占位（LOAD_FAIL 局部重试） ── */
+.pbl-skeleton { height: 60px; border-radius: 4px; background: linear-gradient(90deg, #f2f3f5 25%, #e9eaec 37%, #f2f3f5 63%); background-size: 400% 100%; animation: pbl-sk 1.2s ease infinite; }
+@keyframes pbl-sk { 0% { background-position: 100% 50%; } 100% { background-position: 0 50%; } }
+
+/* ── 只读态（审批挂起 / 权限不足时禁止编辑控件） ── */
+[data-readonly="1"] .pbl-hud-acts button,
+[data-readonly="1"] .pbl-chat-input { opacity: .5; pointer-events: none; }
+
+/* ── 小屏适配：HUD 与导航换行，不遮挡渲染区 ── */
+@media (max-width: 768px) {
+  .pbl-topbar-in { flex-wrap: wrap; }
+  .pbl-navitem { font-size: 12px; padding: 5px 9px; }
+}
diff --git a/wwwroot/overlay/pbl_overlay_core.js b/wwwroot/overlay/pbl_overlay_core.js
new file mode 100644
index 0000000..5efcd1a
--- /dev/null
+++ b/wwwroot/overlay/pbl_overlay_core.js
@@ -0,0 +1,255 @@
+/**
+ * pbl_overlay_core.js —— PBL 前端覆盖层内核（M9 / pbl_scense_ext）
+ *
+ * 纪律（Q1/Q4）：
+ *   ① 不改 scense / scense_game 渲染主循环，本文件只做「注册表 + 组件工厂 + 错误降级 + 时延预算」；
+ *   ② 前端仅渲染 + 发起意图，无本地权威状态，广播到达前不预测渲染；
+ *   ③ 页面/组件/错误态全部注册化，scense 基线升级时只改注册表不改渲染层。
+ *
+ * 暴露：window.PblOverlayCore = {PAGES, COMPONENTS, ERROR_STATES, SEQUENCES, BUDGETS, ...}
+ */
+(function (global) {
+  'use strict';
+
+  /* ───────────────────────── 1. 12 页面注册表（与 pbl_ui_page_registry 同源） ───────────────────────── */
+  // budget_ms: 500 = 世界内覆盖层组件（广播渲染预算）；1500 = 教师侧页面（首屏预算）
+  var PAGES = [
+    { key: 'home',              title: 'PBL 首页',      route: '/pbl_overlay/home.ui',              widget: 'card_grid',      role: 'logined', budget_ms: 1500, in_world: false, seq: ['S1'] },
+    { key: 'blueprint_list',    title: '蓝图列表',      route: '/pbl_overlay/blueprint_list.ui',    widget: 'data_table',     role: 'teacher', budget_ms: 1500, in_world: false, seq: ['S1'] },
+    { key: 'blueprint_editor',  title: '蓝图结构视图',  route: '/pbl_overlay/blueprint_editor.ui',  widget: 'form_tree',      role: 'teacher', budget_ms: 1500, in_world: false, seq: ['S1'] },
+    { key: 'validation_report', title: '校验报告(14维)', route: '/pbl_overlay/validation_report.ui', widget: 'score_panel',    role: 'teacher', budget_ms: 1500, in_world: false, seq: ['S1'] },
+    { key: 'agent_console',     title: 'Agent 控制台',  route: '/pbl_overlay/agent_console.ui',     widget: 'chat_panel',     role: 'teacher', budget_ms: 1500, in_world: false, seq: ['S1'] },
+    { key: 'approval_center',   title: '人工审批中心',  route: '/pbl_overlay/approval_center.ui',   widget: 'approval_list',  role: 'teacher', budget_ms: 1500, in_world: false, seq: ['S1'] },
+    { key: 'play_preview',      title: 'Play 预览',     route: '/pbl_overlay/play_preview.ui',      widget: 'world_overlay',  role: 'logined', budget_ms: 500,  in_world: true,  seq: ['S1', 'S2'] },
+    { key: 'mission_board',     title: '驱动问题板',    route: '/pbl_overlay/mission_board.ui',     widget: 'mission_board',  role: 'logined', budget_ms: 500,  in_world: true,  seq: ['S1', 'S2'] },
+    { key: 'role_panel',        title: '角色面板',      route: '/pbl_overlay/role_panel.ui',        widget: 'role_cards',     role: 'logined', budget_ms: 500,  in_world: true,  seq: ['S2'] },
+    { key: 'artifact_studio',   title: '产出物工坊',    route: '/pbl_overlay/artifact_studio.ui',   widget: 'editor_panel',   role: 'logined', budget_ms: 500,  in_world: true,  seq: ['S3'] },
+    { key: 'evidence_wall',     title: '证据墙',        route: '/pbl_overlay/evidence_wall.ui',     widget: 'evidence_grid',  role: 'logined', budget_ms: 500,  in_world: true,  seq: ['S3', 'S4'] },
+    { key: 'assessment_report', title: '评估报告',      route: '/pbl_overlay/assessment_report.ui', widget: 'rubric_report',  role: 'teacher', budget_ms: 1500, in_world: false, seq: ['S4'] }
+  ];
+
+  /* ───────────────────────── 2. 11 组件注册表（覆盖层内，不侵入渲染层） ───────────────────────── */
+  var COMPONENTS = [
+    { name: 'TopBar',         host: '.pbl-topbar',   pages: ['*'] },
+    { name: 'NavRail',        host: '.pbl-navrail',  pages: ['*'] },
+    { name: 'GoalCard',       host: '.pbl-main',     pages: ['mission_board', 'play_preview'] },
+    { name: 'SceneCard',      host: '.pbl-main',     pages: ['play_preview', 'blueprint_editor'] },
+    { name: 'StepList',       host: '.pbl-main',     pages: ['mission_board', 'blueprint_editor'] },
+    { name: 'RubricEditor',   host: '.pbl-main',     pages: ['assessment_report'] },
+    { name: 'ValidationBadge',host: '.pbl-topbar',   pages: ['*'] },
+    { name: 'ArtifactViewer', host: '.pbl-main',     pages: ['artifact_studio', 'evidence_wall'] },
+    { name: 'ChatPanel',      host: '.pbl-main',     pages: ['agent_console'] },
+    { name: 'ApprovalQueue',  host: '.pbl-main',     pages: ['approval_center'] },
+    { name: 'HudOverlay',     host: '.pbl-hud',      pages: ['*'] }
+  ];
+
+  /* ───────────────────────── 3. 9 类错误降级态（ui-design.md §4 错误提示） ───────────────────────── */
+  var ERROR_STATES = {
+    NET_FAIL:         { title: '网络中断',    desc: '显示缓存数据 + 重试按钮',        tone: 'warn',  retry: true,  action: 'retry' },
+    AUTH_FAIL:        { title: '登录失效',    desc: '请重新登录，草稿已本地保留',      tone: 'error', retry: false, action: 'relogin' },
+    LOAD_FAIL:        { title: '数据加载失败', desc: '骨架占位 + 局部重试',            tone: 'error', retry: true,  action: 'retry' },
+    VALIDATE_BLOCK:   { title: '质量门禁未过', desc: '已阻断编译，请查看校验报告',      tone: 'block', retry: false, action: 'goto-validation' },
+    APPROVAL_PENDING: { title: '待人工审批',   desc: '操作已挂起，等待审批单裁决',      tone: 'block', retry: false, action: 'goto-approval' },
+    LLM_FALLBACK:     { title: 'LLM 不可用',   desc: '已切换离线模板兜底（template_fallback）', tone: 'warn', retry: false, action: 'none' },
+    RATE_LIMIT:       { title: '请求过于频繁', desc: '退避倒计时后自动重试',            tone: 'warn',  retry: true,  action: 'backoff' },
+    SESSION_ENDED:    { title: '会话已结束',   desc: '进入只读回放模式',                tone: 'info',  retry: false, action: 'readonly' },
+    RENDER_DEGRADED:  { title: '渲染降级',     desc: '覆盖层保留，2D 占位图渲染',        tone: 'warn',  retry: false, action: 'none' }
+  };
+
+  // 后端错误码 → 前端降级态（pbl_common §4 错误码文案映射）
+  var ERROR_CODE_MAP = {
+    'PBL_E_FORBIDDEN': 'AUTH_FAIL',
+    'PBL_E_UNAUTHORIZED': 'AUTH_FAIL',
+    'PBL_E_TENANT_MISSING': 'AUTH_FAIL',
+    'PBL_E_TIMEOUT': 'NET_FAIL',
+    'PBL_E_NETWORK': 'NET_FAIL',
+    'PBL_E_NOT_FOUND': 'LOAD_FAIL',
+    'PBL_FEEDBACK_TYPE_INVALID': 'LOAD_FAIL',
+    'PBL_VALIDATION_BLOCK': 'VALIDATE_BLOCK',
+    'PBL_APPROVAL_PENDING': 'APPROVAL_PENDING',
+    'PBL_LLM_UNAVAILABLE': 'LLM_FALLBACK',
+    'PBL_RATE_LIMIT': 'RATE_LIMIT',
+    'PBL_SESSION_ENDED': 'SESSION_ENDED',
+    'PBL_RENDER_DEGRADED': 'RENDER_DEGRADED'
+  };
+
+  /* ───────────────────────── 4. 4 组交互时序（§4 学生玩家页交互契约） ───────────────────────── */
+  var SEQUENCES = {
+    S1: { name: 'enter_world',    desc: '进入世界：bootstrap → GD/状态快照 → 首屏渲染（≤1500ms）',
+          steps: ['pbl_overlay_bootstrap', 'gd_snapshot_render', 'first_screen_gate'] },
+    S2: { name: 'intent_broadcast', desc: '做任务：submit_intent → 广播回传 → 覆盖层更新（≤500ms）',
+          steps: ['submit_intent', 'broadcast_recv', 'overlay_patch_gate'] },
+    S3: { name: 'artifact_evidence', desc: '产出物：create_artifact → submit_artifact → collect_evidence（幂等）',
+          steps: ['create_artifact', 'submit_artifact', 'collect_evidence'] },
+    S4: { name: 'feedback_reflection', desc: '反思/反馈：pbl_playtest_feedback_save（feedback|reflection）',
+          steps: ['open_form', 'validate', 'save'] }
+  };
+
+  /* ───────────────────────── 5. 时延预算（Performance API 实测，超预算打横幅） ───────────────────────── */
+  var BUDGETS = {
+    first_screen_ms: 1500,   // 首屏
+    broadcast_render_ms: 500, // 广播到达 → 覆盖层 DOM 更新完成
+    poll_interval_ms: 1000,   // 长轮询节拍（SSE 不可用时降级）
+    intent_timeout_ms: 8000
+  };
+
+  /* ───────────────────────── 6. 工具函数 ───────────────────────── */
+  function byKey(k) {
+    for (var i = 0; i < PAGES.length; i++) { if (PAGES[i].key === k) { return PAGES[i]; } }
+    return null;
+  }
+
+  function pagesOfRole(role) {
+    return PAGES.filter(function (p) {
+      if (p.role === 'logined') { return true; }
+      return p.role === role;
+    });
+  }
+
+  function esc(s) {
+    return String(s === null || s === undefined ? '' : s)
+      .replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
+      .replace(/"/g, '&quot;').replace(/'/g, '&#39;');
+  }
+
+  function now() {
+    return (global.performance && performance.now) ? performance.now() : Date.now();
+  }
+
+  /** 时延计录器：mark 起 / stop 止，超预算回调 onOver(ms) */
+  function Chrono(label, budgetMs, onOver) {
+    this.label = label;
+    this.budget = budgetMs;
+    this.t0 = now();
+    this.onOver = onOver;
+    this.done = false;
+  }
+  Chrono.prototype.stop = function (extra) {
+    if (this.done) { return this.cost(); }
+    var cost = now() - this.t0;
+    this._cost = cost;
+    this.done = true;
+    global.__PBL_PERF__ = global.__PBL_PERF__ || {};
+    global.__PBL_PERF__[this.label] = Math.round(cost);
+    if (this.budget && cost > this.budget && typeof this.onOver === 'function') {
+      this.onOver(cost, extra);
+    }
+    return cost;
+  };
+  Chrono.prototype.cost = function () { return this._cost === undefined ? (now() - this.t0) : this._cost; };
+
+  /* ───────────────────────── 7. 事件总线（只监听/派发，不介入渲染主循环） ───────────────────────── */
+  var Bus = {
+    /** 监听基座事件（scense:ready / scense:entity-clicked / scense:state-applied ...） */
+    on: function (name, fn) {
+      global.addEventListener(name, fn);
+      return function () { global.removeEventListener(name, fn); };
+    },
+    /** 派发覆盖层事件（pbl:* 前缀，基座与第三方页面可订阅） */
+    emit: function (name, detail) {
+      var evt;
+      try {
+        evt = new CustomEvent(name, { detail: detail || {}, bubbles: true, cancelable: false });
+      } catch (e) {
+        evt = document.createEvent('CustomEvent');
+        evt.initCustomEvent(name, true, false, detail || {});
+      }
+      document.dispatchEvent(evt);
+      return evt;
+    }
+  };
+
+  /* ───────────────────────── 8. 错误降级管理器 ───────────────────────── */
+  function DegradeManager(root, handlers) {
+    this.root = root;
+    this.handlers = handlers || {};
+    this.active = {};      // key -> true
+    this.backoffUntil = 0;
+  }
+  DegradeManager.prototype.show = function (key, opts) {
+    var st = ERROR_STATES[key];
+    if (!st) { return false; }
+    this.active[key] = true;
+    this.ensureBanner();
+    var cls = 'pbl-banner pbl-banner-' + st.tone + (opts && opts.transient ? ' pbl-transient' : '');
+    var btn = st.retry
+      ? '<button class="pbl-banner-btn" data-act="' + st.action + '">' + (st.action === 'backoff' ? '稍后自动重试' : '重试') + '</button>'
+      : (st.action === 'none' ? '' : '<button class="pbl-banner-btn" data-act="' + st.action + '">前往处理</button>');
+    var el = document.createElement('div');
+    el.className = cls;
+    el.setAttribute('data-error-state', key);
+    el.innerHTML = '<b>' + esc(st.title) + '</b><span>' + esc((opts && opts.detail) || st.desc) + '</span>' + btn;
+    this.bannerHost.appendChild(el);
+    var self = this;
+    el.addEventListener('click', function (e) {
+      var act = (e.target && e.target.getAttribute && e.target.getAttribute('data-act')) || '';
+      if (!act) { return; }
+      var h = self.handlers[act];
+      if (typeof h === 'function') { h(e); }
+      if (act === 'retry') { self.hide(key); }
+    });
+    if (opts && opts.transient) {
+      global.setTimeout(function () { self.hide(key); }, opts.ms || 4000);
+    }
+    Bus.emit('pbl:degrade', { state: key, tone: st.tone });
+    return true;
+  };
+  DegradeManager.prototype.hide = function (key) {
+    delete this.active[key];
+    if (!this.bannerHost) { return; }
+    var list = this.bannerHost.querySelectorAll('[data-error-state="' + key + '"]');
+    for (var i = 0; i < list.length; i++) { list[i].parentNode.removeChild(list[i]); }
+  };
+  DegradeManager.prototype.mapCode = function (code) { return ERROR_CODE_MAP[code] || 'LOAD_FAIL'; };
+  DegradeManager.prototype.fromError = function (err) {
+    var code = (err && (err.code || err.error_code)) || '';
+    var key = this.mapCode(code);
+    return this.show(key, { detail: (err && (err.message || err.msg)) || '' });
+  };
+  DegradeManager.prototype.ensureBanner = function () {
+    if (this.bannerHost && this.bannerHost.parentNode) { return; }
+    this.bannerHost = document.createElement('div');
+    this.bannerHost.className = 'pbl-banners';
+    this.root.appendChild(this.bannerHost);
+  };
+  DegradeManager.prototype.setReadonly = function (on) {
+    this.readonly = !!on;
+    if (this.root) { this.root.setAttribute('data-readonly', on ? '1' : '0'); }
+  };
+
+  /* ───────────────────────── 9. 组件工厂（覆盖层内 DOM 组件，与渲染层解耦） ───────────────────────── */
+  function Components() { this.defs = {}; }
+  Components.prototype.register = function (name, render) {
+    this.defs[name] = render;
+    return this;
+  };
+  Components.prototype.render = function (name, host, model) {
+    var fn = this.defs[name];
+    if (!fn || !host) { return false; }
+    var t0 = now();
+    fn(host, model || {});
+    host.setAttribute('data-c-rendered', name);
+    host.setAttribute('data-c-cost-ms', String(Math.round(now() - t0)));
+    return true;
+  };
+  Components.prototype.has = function (name) { return !!this.defs[name]; };
+  Components.prototype.registered = function () { return Object.keys(this.defs); };
+
+  global.PblOverlayCore = {
+    VERSION: '1.0.0',
+    PAGES: PAGES,
+    COMPONENTS: COMPONENTS,
+    ERROR_STATES: ERROR_STATES,
+    ERROR_CODE_MAP: ERROR_CODE_MAP,
+    SEQUENCES: SEQUENCES,
+    BUDGETS: BUDGETS,
+    byKey: byKey,
+    pagesOfRole: pagesOfRole,
+    esc: esc,
+    now: now,
+    Chrono: Chrono,
+    Bus: Bus,
+    DegradeManager: DegradeManager,
+    Components: Components
+  };
+})(window);
diff --git a/wwwroot/overlay/pbl_overlay_loader.js b/wwwroot/overlay/pbl_overlay_loader.js
new file mode 100644
index 0000000..b6b4066
--- /dev/null
+++ b/wwwroot/overlay/pbl_overlay_loader.js
@@ -0,0 +1,71 @@
+/* ============================================================================
+ * pbl_overlay_loader.js —— 覆盖层脚本/CSS 按需注入器（M9）
+ *
+ * 为什么需要它：bricks .ui 页面禁止硬写 <script>/<link> 标签（会绕过 RBAC 或
+ * 触发 403）。本 loader 由页面壳的 bricks `script` actiontype 在用户点击
+ * 「启用 PBL 覆盖层」时调用，动态注入同模块 wwwroot/overlay 下的 JS/CSS
+ * （这些路径已在 scripts/load_path.py 显式注册为 any/logined），注入完成后
+ * 调用 PblOverlayPlay.boot() 完成装配。
+ *
+ * 铁律：只注入本模块静态资源，不改写宿主（scense/scense_game）渲染层任何脚本。
+ * ==========================================================================*/
+(function (global) {
+  'use strict';
+
+  var BASE = String(global.__PBL_API_BASE__ || '').replace(/\/$/, '');
+  var DIR = BASE + '/pbl_scense_ext/overlay/';
+
+  // 依赖顺序：core → transport → play（play 内部依赖前两者）
+  var FILES = ['pbl_overlay_core.js', 'pbl_overlay_transport.js', 'pbl_overlay_play.js'];
+  var CSS = 'pbl_overlay.css';
+
+  var injected = {};
+  var loading = null;
+
+  function loadOne(src) {
+    return new Promise(function (resolve, reject) {
+      if (injected[src]) { return resolve(true); }
+      var s = document.createElement('script');
+      s.src = src;
+      s.async = false;
+      s.onload = function () { injected[src] = true; resolve(true); };
+      s.onerror = function () { reject({ code: 'PBL_E_NETWORK', message: '资源加载失败 ' + src }); };
+      document.head.appendChild(s);
+    });
+  }
+
+  function ensureCss() {
+    var id = 'pbl-overlay-css';
+    if (document.getElementById(id)) { return; }
+    var l = document.createElement('link');
+    l.id = id;
+    l.rel = 'stylesheet';
+    l.href = DIR + CSS;
+    document.head.appendChild(l);
+  }
+
+  function load() {
+    ensureCss();
+    if (loading) { return loading; }
+    loading = FILES.reduce(function (p, f) {
+      return p.then(function () { return loadOne(DIR + f); });
+    }, Promise.resolve());
+    return loading;
+  }
+
+  // 幂等启动：已存在实例则复用（切换页面上下文时可 destroy 后重建）
+  function start(opts) {
+    return load().then(function () {
+      if (!global.PblOverlayPlay) { throw { code: 'PBL_E_NOT_FOUND', message: 'PblOverlayPlay 未注册' }; }
+      if (global.__PBL_OVERLAY__ && global.__PBL_OVERLAY__.mounted) { return global.__PBL_OVERLAY__; }
+      return global.PblOverlayPlay.boot(opts || {}) || global.__PBL_OVERLAY__;
+    });
+  }
+
+  global.PblOverlayLoader = {
+    DIR: DIR,
+    FILES: FILES,
+    load: load,
+    start: start
+  };
+})(window);
diff --git a/wwwroot/overlay/pbl_overlay_play.js b/wwwroot/overlay/pbl_overlay_play.js
new file mode 100644
index 0000000..2830a6b
--- /dev/null
+++ b/wwwroot/overlay/pbl_overlay_play.js
@@ -0,0 +1,776 @@
+/* ============================================================================
+ * pbl_overlay_play.js —— M9 覆盖层装配 + 事件处理器（scense / scense_game 侧）
+ *
+ * 铁律：
+ *  1. 不修改 scense/scense_game 渲染主循环 —— 只做「外挂」：探测宿主只读钩子
+ *     （window.scenseGame / CustomEvent），钩子缺失时降级为契约轮询，绝不
+ *     包裹/注入宿主帧函数（requestAnimationFrame 链不劫持）。
+ *  2. 广播到达 → 覆盖层 DOM 更新完成 ≤ 500ms（BUDGETS.broadcast_render_ms），
+ *     超预算打 RENDER_DEGRADED 横幅并自适应节流合并补丁，不丢数据、不静默。
+ *  3. 首屏 ≤ 1500ms（BUDGETS.first_screen_ms），超时走 LOAD_FAIL 骨架 + 局部重试。
+ *  4. 网络交互只走 pbl_overlay_transport.js 契约端点（pbl_* 模块 .dspy）。
+ *
+ * 依赖加载顺序：pbl_overlay_core.js → pbl_overlay_transport.js → 本文件
+ * API 对齐：Core.Bus（全局单例，on=window 监听 / emit=document CustomEvent）、
+ *          Core.Chrono(label,budget,onOver).stop()、
+ *          Core.DegradeManager(root).show(key,{detail})/.fromError(err)、
+ *          Tpt.Transport({session_id,blueprint_id,onEvent,onDegrade,onPerf})
+ * ==========================================================================*/
+(function (global) {
+  'use strict';
+
+  var Core = global.PblOverlayCore;
+  var Tpt = global.PblOverlayTransport;
+  if (!Core || !Tpt) {
+    if (global.console) { console.error('[pbl_overlay_play] core/transport 未加载'); }
+    return;
+  }
+
+  var BUDGETS = Core.BUDGETS;
+  var esc = Core.esc;
+  var now = Core.now;
+
+  /* ───────────────────────── 1. 页面路由解析（注册表 route → 实际 URL） ───────────────────────── */
+  // 设计注册表 route 形如 /pbl_overlay/mission_board.ui；
+  // 模块自动路由实际为 /pbl_scense_ext/pbl_overlay/mission_board.ui
+  var MODULE_PREFIX = '/pbl_scense_ext';
+
+  function pageUrl(page) {
+    var route = (page && page.route) || '';
+    if (!route) { return ''; }
+    if (route.indexOf(MODULE_PREFIX + '/') === 0) { return Tpt.apiBase() + route; }
+    if (route.charAt(0) === '/') { return Tpt.apiBase() + MODULE_PREFIX + route; }
+    return Tpt.apiBase() + MODULE_PREFIX + '/pbl_overlay/' + route;
+  }
+
+  function readQuery() {
+    var out = {};
+    var qs = String(location.search || '').replace(/^\?/, '');
+    if (!qs) { return out; }
+    qs.split('&').forEach(function (kv) {
+      if (!kv) { return; }
+      var i = kv.indexOf('=');
+      var k = i < 0 ? kv : kv.slice(0, i);
+      var v = i < 0 ? '' : kv.slice(i + 1);
+      try {
+        out[decodeURIComponent(k)] = decodeURIComponent(v.replace(/\+/g, ' '));
+      } catch (e) { out[k] = v; }
+    });
+    return out;
+  }
+
+  function hostPageKey() {
+    var el = document.querySelector('[data-pbl-page]');
+    if (el && el.getAttribute('data-pbl-page')) { return el.getAttribute('data-pbl-page'); }
+    var m = String(location.pathname).match(/\/pbl_overlay\/([a-z_]+)\.ui/);
+    if (m) { return m[1]; }
+    return readQuery().page || 'play_preview';
+  }
+
+  function readContext() {
+    // 上下文优先级：宿主注入 __PBL_OVERLAY_CTX__ > URL query > 覆盖层本地草稿
+    var inj = global.__PBL_OVERLAY_CTX__ || {};
+    var q = readQuery();
+    var draft = {};
+    try { draft = JSON.parse(global.localStorage.getItem('pbl.overlay.ctx') || '{}') || {}; } catch (e) { draft = {}; }
+    var ctx = {
+      page: q.page || inj.page || null,
+      session_id: q.session_id || inj.session_id || draft.session_id || null,
+      blueprint_id: q.blueprint_id || inj.blueprint_id || draft.blueprint_id || null,
+      world_id: q.world_id || inj.world_id || draft.world_id || null,
+      role: inj.role || q.role || null
+    };
+    try {
+      global.localStorage.setItem('pbl.overlay.ctx', JSON.stringify({
+        session_id: ctx.session_id, blueprint_id: ctx.blueprint_id, world_id: ctx.world_id
+      }));
+    } catch (e) { /* 隐私模式忽略 */ }
+    return ctx;
+  }
+
+  /* ───────────────────────── 2. scense / scense_game 只读桥（不改渲染主循环） ───────────────────────── */
+  var ScenseBridge = {
+    renderer: function () {
+      return global.scenseGame || global.SCENSE_GAME || global.__SCENSE_RUNTIME__ || null;
+    },
+    // 仅探测宿主状态，不写回
+    hasRenderer: function () { return !!this.renderer(); },
+    rendererStatus: function () {
+      var g = this.renderer();
+      if (!g) { return { available: false, paused: null, entities: 0 }; }
+      var n = 0;
+      if (typeof g.entityCount === 'number') { n = g.entityCount; }
+      else if (g.entities && g.entities.length !== undefined) { n = g.entities.length; }
+      return { available: true, paused: (typeof g.paused === 'boolean') ? g.paused : null, entities: n };
+    },
+    // 订阅宿主广播的 CustomEvent（宿主没有该事件时零副作用，靠 transport 通道兜底）
+    onHostEvent: function (handler) {
+      var names = ['scense:entity_updated', 'scense:broadcast', 'scense:state-applied', 'pbl:broadcast'];
+      names.forEach(function (n) {
+        try {
+          global.addEventListener(n, function (ev) { handler((ev && ev.detail) || {}); }, false);
+        } catch (e) { /* 忽略 */ }
+      });
+    },
+    // Play 控制：优先宿主 API（只调用不修改），否则回落 scense_game 契约端点
+    control: function (action, ctx) {
+      var g = this.renderer();
+      if (g && typeof g[action] === 'function') {
+        try {
+          var r = g[action]();
+          if (r && typeof r.then === 'function') { return r; }
+          return Promise.resolve({ status: 'ok', via: 'host', action: action });
+        } catch (e) { /* 继续走契约 */ }
+      }
+      var map = {
+        start: 'game_start', pause: 'game_pause', resume: 'game_resume',
+        restart: 'game_restart', end: 'game_end'
+      };
+      var ep = map[action];
+      if (!ep) { return Promise.reject({ code: 'PBL_E_NOT_FOUND', message: '未知控制 ' + action }); }
+      return fetch(Tpt.apiBase() + '/scense_game/game/api/' + ep + '.dspy', {
+        method: 'POST', credentials: 'same-origin',
+        headers: { 'Content-Type': 'application/json;charset=UTF-8' },
+        body: JSON.stringify({
+          session_id: (ctx && ctx.session_id) || '',
+          world_id: (ctx && ctx.world_id) || ''
+        })
+      }).then(function (r) {
+        if (!r.ok) { return { status: 'fail', code: 'PBL_E_NETWORK', message: 'HTTP ' + r.status }; }
+        return r.json();
+      });
+    }
+  };
+
+  /* ───────────────────────── 3. 覆盖层实例 ───────────────────────── */
+  function Overlay(opts) {
+    opts = opts || {};
+    this.pageKey = opts.page || hostPageKey() || 'play_preview';
+    this.page = Core.byKey(this.pageKey) || Core.byKey('play_preview');
+    this.ctx = opts.context || readContext();
+    this.chrono = new Core.Chrono('first_screen', BUDGETS.first_screen_ms, function (ms) {
+      if (global.__PBL_OVERLAY__) {
+        global.__PBL_OVERLAY__.degrade.show('RENDER_DEGRADED', { detail: '首屏 ' + Math.round(ms) + 'ms 超预算 ' + BUDGETS.first_screen_ms + 'ms' });
+      }
+    });
+    this.degrade = new Core.DegradeManager(opts.root || this.pageRoot());
+    this.components = new Core.Components();
+    this.transport = null;
+    this.model = {};
+    this.patchQueue = [];
+    this.patchScheduled = false;
+    this.lastPatchCost = 0;
+    this.throttleMs = 0;              // 超预算后自适应节流
+    this.mounted = false;
+    this.destroyed = false;
+    this.perf = { first_screen_ms: null, broadcast_render_ms: null };
+    this.emitter = document;           // 局部事件走 document CustomEvent（pbl-ov:* 前缀）
+    this._unsubs = [];
+    this.registerBuiltinComponents();
+    this.registerEventHandlers();
+  }
+
+  Overlay.prototype.pageRoot = function () {
+    return document.querySelector('[data-pbl-overlay-root]') || document.body;
+  };
+
+  /* ── 局部事件总线（不占用全局 Bus 命名空间，避免与宿主事件混淆） ── */
+  Overlay.prototype.on = function (name, fn) {
+    var h = function (ev) { fn((ev && ev.detail) || {}); };
+    this.emitter.addEventListener(name, h, false);
+    this._unsubs.push([name, h]);
+    return this;
+  };
+  Overlay.prototype.emit = function (name, detail) {
+    return Core.Bus.emit('pbl-ov:' + name, detail);
+  };
+
+  Overlay.prototype.mount = function () {
+    if (this.mounted) { return Promise.resolve(this); }
+    this.mounted = true;
+    var self = this;
+    this.transport = new Tpt.Transport({
+      session_id: this.ctx.session_id,
+      blueprint_id: this.ctx.blueprint_id,
+      since_seq: 0,
+      onEvent: function (item) { self.ingestTransport(item); },
+      onDegrade: function (code, msg) { self.degrade.show(self.degrade.mapCode(code), { detail: msg || '' }); },
+      onPerf: function (name, ms) { self.perf[name] = ms; }
+    });
+
+    // S1：bootstrap → 首屏渲染（≤1500ms 门禁由 Chrono 自动判定）
+    return this.transport.bootstrap({ world_id: this.ctx.world_id, page: this.pageKey })
+      .then(function (d) {
+        self.model = normalizeBootstrap(d);
+        self.degrade.hide('LOAD_FAIL');
+        self.renderAll();
+        self.chrono.stop();
+        self.startStreams();
+        self.writePerfBadge();
+        return self;
+      })
+      .catch(function (err) {
+        self.degrade.fromError(err);
+        // 断网/超时：用本地缓存模型渲染骨架，保证首屏不完全空白 + 局部重试按钮
+        self.model = cachedModel(self.pageKey);
+        self.renderAll(true);
+        self.chrono.stop();
+        self.startStreams();
+        self.writePerfBadge();
+        return self;
+      });
+  };
+
+  // 事件流：transport（SSE→长轮询自动降级）+ 宿主 CustomEvent（只读旁路）
+  Overlay.prototype.startStreams = function () {
+    var self = this;
+    this.transport.subscribe();
+    ScenseBridge.onHostEvent(function (detail) { self.ingestHost(detail); });
+
+    // 重试按钮（core DegradeManager banner 事件委托：data-act=retry 会派发 pbl:degrade-retry）
+    Core.Bus.on('pbl:degrade-retry', function () {
+      self.retryLast();
+    });
+    this.on('navigate', function (p) { self.navigate(p && p.page); });
+    this.on('control', function (p) {
+      ScenseBridge.control(p && p.action, self.ctx).then(function (res) {
+        if (res && res.status === 'fail') {
+          self.degrade.show(self.degrade.mapCode(res.code || 'PBL_E_NETWORK'), { detail: res.message || '' });
+        } else {
+          self.degrade.show('SESSION_ENDED', { detail: '控制指令已下发：' + (p && p.action), transient: true });
+        }
+      }).catch(function (e) { self.degrade.fromError(e); });
+    });
+  };
+
+  Overlay.prototype.retryLast = function () {
+    var self = this;
+    return this.transport.bootstrap({ world_id: this.ctx.world_id, page: this.pageKey })
+      .then(function (d) {
+        self.model = normalizeBootstrap(d);
+        self.degrade.hide('LOAD_FAIL');
+        self.degrade.hide('NET_FAIL');
+        self.renderAll();
+        return d;
+      })
+      .catch(function (e) { self.degrade.fromError(e); });
+  };
+
+  /* ───────────────────────── 4. 广播 → 覆盖层补丁（≤500ms 门禁 + 自适应节流） ───────────────────────── */
+  // transport 通道：item = {seq,event_type,entity_id,payload,received_at}
+  Overlay.prototype.ingestTransport = function (item) {
+    var patch = normalizeTransportPatch(item);
+    if (!patch) { return; }
+    this.patchQueue.push(patch);
+    this.schedulePatch();
+  };
+
+  // 宿主 CustomEvent 旁路（无 seq，仅做展示层增量，不参与权威状态）
+  Overlay.prototype.ingestHost = function (detail) {
+    if (!detail || (detail.seq !== undefined && detail.seq !== null)) { return; } // 带 seq 的走 transport
+    this.patchQueue.push(normalizeHostPatch(detail));
+    this.schedulePatch();
+  };
+
+  Overlay.prototype.schedulePatch = function () {
+    var self = this;
+    if (this.patchScheduled) { return; }
+    this.patchScheduled = true;
+    var wait = this.throttleMs;
+    var raf = global.requestAnimationFrame || function (fn) { return global.setTimeout(fn, 16); };
+    global.setTimeout(function () { raf(function () { self.flushPatches(); }); }, wait);
+  };
+
+  Overlay.prototype.flushPatches = function () {
+    this.patchScheduled = false;
+    if (this.destroyed || !this.patchQueue.length) { return; }
+    var batch = this.patchQueue.splice(0, this.patchQueue.length);
+    var t0 = now();
+    for (var i = 0; i < batch.length; i++) { this.applyPatch(batch[i]); }
+    this.renderDynamic();
+    persistModel(this.pageKey, this.model);
+    var cost = Math.round(now() - t0);
+    this.lastPatchCost = cost;
+    this.perf.broadcast_render_ms = cost;
+    this.writePerfBadge();
+    if (cost > BUDGETS.broadcast_render_ms) {
+      // 超预算：横幅 + 自适应节流（合并更多补丁），不丢数据
+      this.throttleMs = Math.min(2000, Math.max(200, this.throttleMs + 200));
+      this.degrade.show('RENDER_DEGRADED', {
+        detail: '广播渲染 ' + cost + 'ms 超预算 ' + BUDGETS.broadcast_render_ms + 'ms，已合并补丁（节流 ' + this.throttleMs + 'ms）'
+      });
+    } else if (this.throttleMs > 0) {
+      this.throttleMs = Math.max(0, this.throttleMs - 100);
+    }
+  };
+
+  Overlay.prototype.applyPatch = function (patch) {
+    var m = this.model;
+    if (!m || !patch) { return; }
+    if (patch.entity_id) {
+      if (!m.entities) { m.entities = {}; }
+      var prev = m.entities[patch.entity_id] || {};
+      m.entities[patch.entity_id] = Object.assign({}, prev, patch.state || {});
+      m.entities[patch.entity_id].__rev = (prev.__rev || 0) + 1;
+      m.entity_count = Object.keys(m.entities).length;
+    }
+    if (patch.event_type) {
+      if (!m.events) { m.events = []; }
+      m.events.unshift({ type: patch.event_type, text: patch.text || patch.event_type, at: patch.at });
+      if (m.events.length > 50) { m.events.length = 50; }
+    }
+    if (patch.progress !== undefined && patch.progress !== null) { m.progress = Number(patch.progress); }
+    if (patch.quality_state) { m.quality_state = patch.quality_state; }
+    if (patch.artifact) { (m.artifacts = m.artifacts || []).unshift(patch.artifact); }
+    m.lastEvent = patch;
+    this.emit('model-patched', patch);
+  };
+
+  function normalizeTransportPatch(item) {
+    if (!item) { return null; }
+    var p = item.payload || {};
+    return {
+      source: 'broadcast',
+      seq: item.seq,
+      event_type: item.event_type || 'patch',
+      entity_id: item.entity_id || p.entity_id || null,
+      state: p.state || p.patch || null,
+      text: p.text || p.message || item.event_type || '',
+      progress: (p.progress !== undefined) ? p.progress : undefined,
+      quality_state: p.quality_state || null,
+      artifact: p.artifact || null,
+      at: item.received_at || now()
+    };
+  }
+
+  function normalizeHostPatch(detail) {
+    detail = detail || {};
+    return {
+      source: 'host',
+      seq: null,
+      event_type: detail.event_type || detail.type || 'host_patch',
+      entity_id: detail.entity_id || null,
+      state: detail.state || detail.patch || null,
+      text: detail.text || detail.message || '',
+      progress: detail.progress,
+      quality_state: detail.quality_state || null,
+      artifact: detail.artifact || null,
+      at: detail.at || now()
+    };
+  }
+
+  /* ───────────────────────── 5. 11 组件注册 + 渲染（覆盖层内 DOM，不触碰渲染层 canvas） ───────────────────────── */
+  Overlay.prototype.registerBuiltinComponents = function () {
+    var self = this;
+    var C = this.components;
+
+    C.register('TopBar', function (host, m) {
+      host.innerHTML =
+        '<div class="pbl-topbar-in">' +
+        '<span class="pbl-title">' + esc(m.page_title || '') + '</span>' +
+        '<span class="pbl-sub">' + esc(m.blueprint_name || '') + (m.version ? ' v' + esc(m.version) : '') + '</span>' +
+        '<span class="pbl-spacer"></span>' +
+        '<span class="pbl-badge" data-badge="quality">' + esc(m.quality_state || '-') + '</span>' +
+        '<span class="pbl-badge" data-badge="perf">-</span>' +
+        '</div>';
+    });
+
+    C.register('NavRail', function (host, m) {
+      var pages = Core.pagesOfRole(m.role || 'logined');
+      var html = '<nav class="pbl-navrail-in">';
+      for (var i = 0; i < pages.length; i++) {
+        var on = pages[i].key === m.page_key ? ' is-active' : '';
+        html += '<a class="pbl-navitem' + on + '" href="' + esc(self.navHref(pages[i].key)) +
+          '" data-pbl-nav="' + esc(pages[i].key) + '">' + esc(pages[i].title) + '</a>';
+      }
+      host.innerHTML = html + '</nav>';
+    });
+
+    C.register('GoalCard', function (host, m) {
+      var g = m.goal || {};
+      host.insertAdjacentHTML('beforeend',
+        '<section class="pbl-card pbl-goal"><h4>驱动问题 / 目标</h4>' +
+        '<p class="pbl-goal-q">' + esc(g.question || '暂无目标（等待蓝图编译）') + '</p>' +
+        '<p class="pbl-goal-m">' + esc(g.milestone || '') + '</p></section>');
+    });
+
+    C.register('SceneCard', function (host, m) {
+      var s = m.scene || {};
+      host.insertAdjacentHTML('beforeend',
+        '<section class="pbl-card pbl-scene"><h4>当前场景</h4>' +
+        '<p>' + esc(s.name || '-') + ' <em>' + esc(s.kind || '') + '</em></p>' +
+        '<p class="pbl-dim">实体 ' + Number(m.entity_count || 0) + ' · 观察者 ' + Number(m.observer_count || 0) + '</p></section>');
+    });
+
+    C.register('StepList', function (host, m) {
+      var steps = m.steps || [];
+      var html = '<section class="pbl-card pbl-steps"><h4>任务步骤</h4><ol>';
+      for (var i = 0; i < steps.length; i++) {
+        html += '<li class="' + (steps[i].done ? 'is-done' : '') + '">' +
+          esc(steps[i].title || steps[i].name || ('步骤' + (i + 1))) + '</li>';
+      }
+      host.insertAdjacentHTML('beforeend', html + '</ol></section>');
+    });
+
+    C.register('RubricEditor', function (host, m) {
+      var rows = m.rubric || [];
+      var html = '<section class="pbl-card pbl-rubric"><h4>量规（Rubric 加权）</h4>' +
+        '<table><thead><tr><th>维度</th><th>权重</th><th>得分</th></tr></thead><tbody>';
+      for (var i = 0; i < rows.length; i++) {
+        html += '<tr><td>' + esc(rows[i].name || rows[i].dimension || '-') + '</td><td>' +
+          esc(String(rows[i].weight === undefined ? '' : rows[i].weight)) + '</td><td>' +
+          esc(String(rows[i].score === undefined ? '-' : rows[i].score)) + '</td></tr>';
+      }
+      host.insertAdjacentHTML('beforeend', html + '</tbody></table></section>');
+    });
+
+    C.register('ValidationBadge', function (host, m) {
+      var v = m.validation || {};
+      var tone = v.blocked ? 'block' : (v.passed ? 'ok' : 'warn');
+      host.insertAdjacentHTML('beforeend',
+        '<span class="pbl-vbadge is-' + tone + '" title="14 维校验">' +
+        esc(v.summary || v.state || '未校验') + '</span>');
+    });
+
+    C.register('ArtifactViewer', function (host, m) {
+      var list = m.artifacts || [];
+      var html = '<section class="pbl-card pbl-artifacts"><h4>产出物 / 证据</h4><div class="pbl-grid">';
+      for (var i = 0; i < list.length; i++) {
+        html += '<div class="pbl-tile"><strong>' + esc(list[i].name || list[i].artifact_id || ('#' + i)) + '</strong>' +
+          '<span>' + esc(list[i].kind || list[i].evidence_type || '') + '</span>' +
+          '<em>' + esc(list[i].state || list[i].status || '') + '</em></div>';
+      }
+      if (!list.length) { html += '<div class="pbl-empty">暂无产出物</div>'; }
+      html += '</div>' +
+        '<form data-pbl-form="artifact"><input name="artifact_id" placeholder="产出物ID(幂等)">' +
+        '<input name="name" placeholder="名称"><button type="submit">提交并采集证据</button></form></section>';
+      host.insertAdjacentHTML('beforeend', html);
+    });
+
+    C.register('ChatPanel', function (host, m) {
+      var msgs = m.agent_messages || [];
+      var html = '<section class="pbl-card pbl-chat"><h4>Agent 对话</h4><div class="pbl-chat-log">';
+      for (var i = 0; i < msgs.length; i++) {
+        var fb = msgs[i].fallback || msgs[i].template_fallback ? ' is-fallback' : '';
+        html += '<div class="pbl-msg is-' + esc(msgs[i].role || 'agent') + fb + '">' +
+          esc(msgs[i].content || msgs[i].text || '') + '</div>';
+      }
+      html += '</div><div class="pbl-chat-input">' +
+        '<input type="text" data-pbl-chat placeholder="向 Agent 提问…"><button data-pbl-send>发送</button></div></section>';
+      host.insertAdjacentHTML('beforeend', html);
+    });
+
+    C.register('ApprovalQueue', function (host, m) {
+      var items = m.approvals || [];
+      var html = '<section class="pbl-card pbl-approvals"><h4>待人工审批</h4><ul>';
+      for (var i = 0; i < items.length; i++) {
+        html += '<li><span>' + esc(items[i].title || items[i].approval_id || '-') + '</span><em>' +
+          esc(items[i].state || '') + '</em></li>';
+      }
+      if (!items.length) { html += '<li class="pbl-empty">暂无待审批项</li>'; }
+      host.insertAdjacentHTML('beforeend', html + '</ul></section>');
+    });
+
+    C.register('HudOverlay', function (host, m) {
+      var pct = Math.max(0, Math.min(100, Number(m.progress || 0)));
+      host.innerHTML =
+        '<div class="pbl-hud-in">' +
+        '<div class="pbl-hud-progress"><span style="width:' + pct + '%"></span></div>' +
+        '<div class="pbl-hud-role">' + esc(m.role_label || m.role || '') + '</div>' +
+        '<div class="pbl-hud-acts">' +
+        '<button data-pbl-act="start">开始</button><button data-pbl-act="pause">暂停</button>' +
+        '<button data-pbl-act="resume">继续</button><button data-pbl-act="restart">重来</button>' +
+        '<button data-pbl-act="end">结束</button>' +
+        '</div><div class="pbl-hud-feed"></div></div>';
+    });
+  };
+
+  Overlay.prototype.hostFor = function (comp) {
+    var root = this.pageRoot();
+    var cls = comp.host.replace(/^\./, '');
+    var el = root.querySelector('.' + cls);
+    if (!el) {
+      el = document.createElement('div');
+      el.className = cls;
+      if (cls === 'pbl-hud') {
+        var main = root.querySelector('.pbl-main') || ensure(root, 'pbl-main');
+        main.appendChild(el);
+      } else {
+        root.appendChild(el);
+      }
+    }
+    return el;
+  };
+
+  function ensure(parent, cls) {
+    var el = parent.querySelector('.' + cls);
+    if (!el) { el = document.createElement('div'); el.className = cls; parent.appendChild(el); }
+    return el;
+  }
+
+  Overlay.prototype.renderAll = function (skeletonOnly) {
+    var comps = Core.COMPONENTS;
+    var m = Object.assign({}, this.model, {
+      page_key: this.pageKey,
+      page_title: this.page.title,
+      role: this.ctx.role || this.model.role || 'logined'
+    });
+    var allowed = comps.filter(function (c) {
+      return c.pages.indexOf('*') >= 0 || c.pages.indexOf(m.page_key) >= 0;
+    });
+    resetHosts(this.pageRoot());
+    for (var i = 0; i < allowed.length; i++) {
+      var c = allowed[i];
+      if (!this.components.has(c.name)) { continue; }
+      try {
+        this.components.render(c.name, this.hostFor(c), m);
+      } catch (e) {
+        this.degrade.show('RENDER_DEGRADED', { detail: '组件 ' + c.name + ' 渲染失败：' + ((e && e.message) || e) });
+      }
+    }
+    if (skeletonOnly) {
+      ensure(this.pageRoot(), 'pbl-main').insertAdjacentHTML('beforeend', '<div class="pbl-skeleton"></div>');
+    }
+    this.bindDomHandlers();
+    return this;
+  };
+
+  // 增量重绘：只更新随广播变化的 HUD/徽标，保证单次 ≤500ms
+  Overlay.prototype.renderDynamic = function () {
+    var m = this.model;
+    var bar = document.querySelector('.pbl-hud-progress span');
+    if (bar) { bar.style.width = Math.max(0, Math.min(100, Number(m.progress || 0))) + '%'; }
+    var feed = document.querySelector('.pbl-hud-feed');
+    if (feed && m.lastEvent) {
+      var line = document.createElement('div');
+      line.className = 'pbl-feedline';
+      line.textContent = String(m.lastEvent.text || m.lastEvent.event_type || '');
+      feed.insertBefore(line, feed.firstChild);
+      while (feed.childNodes.length > 6) { feed.removeChild(feed.lastChild); }
+    }
+    var badge = document.querySelector('[data-badge="quality"]');
+    if (badge && m.quality_state) { badge.textContent = m.quality_state; }
+    this.emit('rendered', m);
+  };
+
+  function resetHosts(root) {
+    ['.pbl-topbar', '.pbl-navrail', '.pbl-main'].forEach(function (sel) {
+      var el = root.querySelector(sel);
+      if (el) { el.innerHTML = ''; }
+    });
+  }
+
+  function cachedModel(key) {
+    try { return JSON.parse(global.localStorage.getItem('pbl.overlay.model.' + key) || '{}') || {}; }
+    catch (e) { return {}; }
+  }
+
+  function persistModel(key, model) {
+    try {
+      global.localStorage.setItem('pbl.overlay.model.' + key, JSON.stringify({
+        quality_state: model.quality_state, progress: model.progress,
+        artifacts: (model.artifacts || []).slice(0, 20),
+        events: (model.events || []).slice(0, 20)
+      }));
+    } catch (e) { /* 配额/隐私模式忽略 */ }
+  }
+
+  function normalizeBootstrap(d) {
+    d = d || {};
+    var entities = toEntityMap(d.entities);
+    return {
+      role: d.role || null,
+      role_label: d.role_label || d.role_name || null,
+      blueprint_name: d.blueprint_name || (d.blueprint && d.blueprint.name) || '',
+      version: d.version || (d.blueprint && d.blueprint.version) || '',
+      quality_state: d.quality_state || d.quality || '',
+      goal: d.goal || (d.mission ? { question: d.mission.question, milestone: d.mission.milestone } : {}),
+      scene: d.scene || d.current_scene || {},
+      steps: d.steps || d.tasks || [],
+      artifacts: d.artifacts || [],
+      rubric: d.rubric || [],
+      approvals: d.approvals || [],
+      agent_messages: d.agent_messages || d.messages || [],
+      validation: d.validation || {},
+      entities: entities,
+      entity_count: (d.entity_count !== undefined) ? d.entity_count : Object.keys(entities).length,
+      observer_count: d.observer_count || 0,
+      progress: Number(d.progress || 0),
+      recent_events: d.recent_events || []
+    };
+  }
+
+  function toEntityMap(list) {
+    var out = {};
+    if (!list) { return out; }
+    if (list instanceof Array) {
+      for (var i = 0; i < list.length; i++) {
+        var e = list[i];
+        if (e && e.entity_id) { out[e.entity_id] = e; }
+      }
+    } else if (typeof list === 'object') {
+      Object.keys(list).forEach(function (k) { out[k] = list[k]; });
+    }
+    return out;
+  }
+
+  /* ───────────────────────── 6. 4 组交互时序的事件处理器 ───────────────────────── */
+  Overlay.prototype.registerEventHandlers = function () {
+    var self = this;
+
+    // S2 做任务：意图上行（服务端权威回传 seq 后才落补丁，不预测渲染）
+    this.on('intent-submit', function (payload) {
+      return self.transport.submitIntent({
+        type: payload.intent_type || 'action',
+        action: payload.intent || 'interact',
+        entity_id: payload.target_entity_id || payload.entity_id || '',
+        payload: payload.payload || {}
+      }).catch(function (e) { self.degrade.fromError(e); });
+    });
+
+    // S3 产出物：create → submit → collect_evidence（artifact_id 幂等，失败可重试）
+    this.on('artifact-create', function (a) {
+      return self.transport.createArtifact(a)
+        .then(function (res) {
+          var id = (res && (res.artifact_id || (res.data && res.data.artifact_id))) || a.artifact_id;
+          return self.transport.submitArtifact(id);
+        })
+        .then(function () {
+          return self.transport.collectEvidence({
+            evidence_type: a.evidence_type || 'artifact_version', source_id: a.artifact_id || ''
+          });
+        })
+        .catch(function (e) { self.degrade.fromError(e); });
+    });
+
+    // S4 反思 / 反馈
+    this.on('feedback-save', function (f) {
+      return self.transport.saveFeedback(f).catch(function (e) { self.degrade.fromError(e); });
+    });
+
+    // 门禁跳转（VALIDATE_BLOCK / APPROVAL_PENDING 横幅「前往处理」）
+    Core.Bus.on('pbl:degrade', function (ev) {
+      var d = (ev && ev.detail) || {};
+      if (d.state === 'VALIDATE_BLOCK') { /* 用户点横幅按钮时才跳转，此处只标记 */ }
+      if (d.state === 'SESSION_ENDED') { self.degrade.setReadonly(true); }
+    });
+    this.on('goto-page', function (p) { self.navigate(p && p.page); });
+  };
+
+  Overlay.prototype.navHref = function (key) {
+    var p = Core.byKey(key);
+    if (!p) { return '#'; }
+    var url = pageUrl(p);
+    var sep = url.indexOf('?') >= 0 ? '&' : '?';
+    return url + sep + 'session_id=' + encodeURIComponent(this.ctx.session_id || '') +
+      '&blueprint_id=' + encodeURIComponent(this.ctx.blueprint_id || '') +
+      '&world_id=' + encodeURIComponent(this.ctx.world_id || '');
+  };
+
+  Overlay.prototype.navigate = function (key) {
+    var p = Core.byKey(key || '');
+    if (!p) { return; }
+    location.href = this.navHref(p.key);
+  };
+
+  Overlay.prototype.bindDomHandlers = function () {
+    var self = this;
+    var root = this.pageRoot();
+    if (root.getAttribute('data-pbl-bound') === '1') { return; }
+    root.setAttribute('data-pbl-bound', '1');
+
+    root.addEventListener('click', function (ev) {
+      var t = ev.target;
+      if (!t) { return; }
+      var act = closestAttr(t, 'data-pbl-act');
+      if (act) { ev.preventDefault(); self.emit('control', { action: act }); return; }
+      var nav = closestAttr(t, 'data-pbl-nav');
+      if (nav) { /* a[href] 已带上下文参数，交给浏览器跳转 */ return; }
+      var send = closestAttr(t, 'data-pbl-send');
+      if (send !== null) {
+        var inp = root.querySelector('[data-pbl-chat]');
+        var text = inp ? String(inp.value || '').trim() : '';
+        if (!text) { return; }
+        self.emit('intent-submit', { intent: 'ask_agent', payload: { text: text } });
+        if (inp) { inp.value = ''; }
+      }
+    }, false);
+
+    root.addEventListener('submit', function (ev) {
+      var kind = closestAttr(ev.target, 'data-pbl-form');
+      if (!kind) { return; }
+      ev.preventDefault();
+      var data = formToObj(ev.target);
+      if (kind === 'feedback') { self.emit('feedback-save', data); }
+      if (kind === 'artifact') { self.emit('artifact-create', data); }
+    }, false);
+  };
+
+  function closestAttr(el, attr) {
+    var node = el;
+    while (node && node !== document) {
+      if (node.getAttribute && node.getAttribute(attr) !== null) { return node.getAttribute(attr); }
+      node = node.parentNode;
+    }
+    return null;
+  }
+
+  function formToObj(form) {
+    var out = {};
+    var els = form.querySelectorAll('[name]');
+    for (var i = 0; i < els.length; i++) { out[els[i].name] = els[i].value; }
+    return out;
+  }
+
+  Overlay.prototype.writePerfBadge = function () {
+    var badge = document.querySelector('[data-badge="perf"]');
+    if (!badge) { return; }
+    var fs = this.perf.first_screen_ms === null ? null : Math.round(this.perf.first_screen_ms);
+    var br = this.perf.broadcast_render_ms === null ? null : Math.round(this.perf.broadcast_render_ms);
+    badge.textContent = '首屏' + (fs === null ? '-' : (fs + 'ms')) + ' / 广播' + (br === null ? '-' : (br + 'ms'));
+    var ok = (fs === null || fs <= BUDGETS.first_screen_ms) && (br === null || br <= BUDGETS.broadcast_render_ms);
+    badge.setAttribute('class', 'pbl-badge ' + (ok ? 'is-ok' : 'is-warn'));
+    global.__PBL_PERF__ = global.__PBL_PERF__ || {};
+    global.__PBL_PERF__.overlay = { page: this.pageKey, first_screen_ms: fs, broadcast_render_ms: br };
+  };
+
+  Overlay.prototype.destroy = function () {
+    this.destroyed = true;
+    if (this.transport) { this.transport.stop(); }
+    this.patchQueue.length = 0;
+    this._unsubs.forEach(function (p) { /* document 级监听随页面卸载回收 */ });
+    this._unsubs = [];
+    this.mounted = false;
+  };
+
+  /* ───────────────────────── 7. 自动装配入口 ───────────────────────── */
+  function boot(opts) {
+    opts = opts || {};
+    var root = opts.root || document.querySelector('[data-pbl-overlay-root]') || document.body;
+    if (!root.getAttribute('data-pbl-overlay-root')) { root.setAttribute('data-pbl-overlay-root', '1'); }
+    var ov = new Overlay(Object.assign({ root: root }, opts));
+    global.__PBL_OVERLAY__ = ov;
+    ov.mount();
+    return ov;
+  }
+
+  global.PblOverlayPlay = {
+    VERSION: '1.0.0',
+    Overlay: Overlay,
+    ScenseBridge: ScenseBridge,
+    pageUrl: pageUrl,
+    readContext: readContext,
+    boot: boot,
+    auto: function () {
+      // 只在带 data-pbl-page 标记的覆盖层页面壳里自动装配，普通业务页零副作用
+      if (!document.querySelector('[data-pbl-page]')) { return; }
+      if (global.__PBL_OVERLAY__ && global.__PBL_OVERLAY__.mounted) { return; }
+      boot();
+    }
+  };
+  if (document.readyState === 'loading') {
+    document.addEventListener('DOMContentLoaded', function () { global.PblOverlayPlay.auto(); }, false);
+  } else {
+    global.PblOverlayPlay.auto();
+  }
+})(window);
diff --git a/wwwroot/overlay/pbl_overlay_transport.js b/wwwroot/overlay/pbl_overlay_transport.js
new file mode 100644
index 0000000..dc5f56f
--- /dev/null
+++ b/wwwroot/overlay/pbl_overlay_transport.js
@@ -0,0 +1,266 @@
+/**
+ * pbl_overlay_transport.js —— 覆盖层传输层（M9 / pbl_scense_ext）
+ *
+ * 职责：① 契约调用（bootstrap / 意图上行 / 证据 / 反馈）；② 广播通道（SSE 优先，长轮询降级，
+ * Q-OPEN-6 定稿）；③ seq 幂等去重 + 掉线补齐（get_state_snapshot + poll_events(since)）；
+ * ④ 广播渲染时延预算 ≤500ms 的计时与降级。
+ *
+ * 纪律：本层只搬运数据并派发 pbl:broadcast-received 事件，DOM 更新由 pbl_overlay.js 负责，
+ * 不触碰 scense/scense_game 渲染主循环。
+ */
+(function (global) {
+  'use strict';
+
+  var Core = global.PblOverlayCore;
+  if (!Core) { throw new Error('pbl_overlay_core.js 必须先于 pbl_overlay_transport.js 加载'); }
+
+  var BUDGETS = Core.BUDGETS;
+
+  // 契约端点表（模块自动路由 /{module}/api/{name}.dspy）
+  var ENDPOINTS = {
+    'bootstrap':      '/pbl_scense_ext/api/pbl_overlay_bootstrap.dspy',
+    'page_registry':  '/pbl_scense_ext/api/pbl_page_registry_list.dspy',
+    'session_ctx':    '/pbl_scense_ext/api/pbl_session_context_get.dspy',
+    'feedback_save':  '/pbl_scense_ext/api/pbl_playtest_feedback_save.dspy',
+    // 运行时（pbl_runtime_ext，M11a/M11b 权威实现）
+    'event_poll':     '/pbl_runtime_ext/api/pbl_runtime_event_poll.dspy',
+    'broadcast_pull': '/pbl_runtime_ext/api/pbl_runtime_broadcast_pull.dspy',
+    'entity_state':   '/pbl_runtime_ext/api/pbl_entity_state_get.dspy',
+    'world_broadcast':'/pbl_runtime_ext/api/pbl_world_broadcast.dspy',
+    // 意图上行 / 证据 / 评估（其余 pbl_* 模块契约）
+    'submit_intent':  '/pbl_runtime_ext/api/pbl_world_broadcast.dspy',
+    'entity_apply':   '/pbl_runtime_ext/api/pbl_entity_state_apply.dspy',
+    'evidence_collect': '/pbl_evidence/api/pbl_collect_evidence.dspy',
+    'artifact_create':  '/pbl_evidence/api/pbl_create_artifact.dspy',
+    'artifact_submit':  '/pbl_evidence/api/pbl_submit_artifact.dspy',
+    'assessment_report': '/pbl_assessment/api/pbl_assessment_report.dspy'
+  };
+
+  function apiBase() {
+    // 去掉页面路由尾部，得到应用根（与 scense_game game.js 同策略，不改基线）
+    return (global.__PBL_API_BASE__ || String(location.pathname).replace(/\/(pbl_overlay|game|scense_game)\/.*$/, '')).replace(/\/$/, '');
+  }
+
+  function Transport(opts) {
+    opts = opts || {};
+    this.sessionId = opts.session_id || null;
+    this.blueprintId = opts.blueprint_id || null;
+    this.lastSeq = Number(opts.since_seq || 0);
+    this.pending = {};          // seq -> true（去重）
+    this.sse = null;
+    this.timer = null;
+    this.stopped = false;
+    this.cache = {};            // 断网时供降级态展示缓存数据
+    this.onEvent = opts.onEvent || function () {};
+    this.onDegrade = opts.onDegrade || function () {};
+    this.onPerf = opts.onPerf || function () {};
+  }
+
+  /* ───────────── 1. 契约调用（POST，参数进 params_kw） ───────────── */
+  Transport.prototype.call = function (name, params) {
+    var url = ENDPOINTS[name];
+    if (!url) { return Promise.reject({ code: 'PBL_E_NOT_FOUND', message: '未知契约 ' + name }); }
+    var body = Object.assign({}, params || {});
+    if (this.sessionId && body.session_id === undefined) { body.session_id = this.sessionId; }
+    if (this.blueprintId && body.blueprint_id === undefined) { body.blueprint_id = this.blueprintId; }
+    var ctrl = ('AbortController' in global) ? new AbortController() : null;
+    var to = ctrl ? setTimeout(function () { ctrl.abort(); }, BUDGETS.intent_timeout_ms) : null;
+    var self = this;
+    return fetch(apiBase() + url, {
+      method: 'POST',
+      credentials: 'same-origin',
+      headers: { 'Content-Type': 'application/json;charset=UTF-8' },
+      body: JSON.stringify(body),
+      signal: ctrl ? ctrl.signal : undefined
+    }).then(function (r) {
+      if (to) { clearTimeout(to); }
+      if (r.status === 401 || r.status === 403) { return { status: 'fail', code: 'PBL_E_FORBIDDEN', message: 'HTTP ' + r.status }; }
+      if (r.status === 429) { return { status: 'fail', code: 'PBL_RATE_LIMIT', message: '请求过于频繁' }; }
+      if (!r.ok) { return { status: 'fail', code: 'PBL_E_NETWORK', message: 'HTTP ' + r.status }; }
+      return r.json();
+    }).then(function (res) {
+      if (res && res.status === 'fail') {
+        self.onDegrade(res.code || 'PBL_E_NETWORK', res.message || res.msg || '');
+        var e = new Error(res.message || 'contract fail');
+        e.code = res.code; e.payload = res;
+        throw e;
+      }
+      self.cache[name] = { at: Date.now(), data: res };
+      return res;
+    }).catch(function (err) {
+      if (err && err.name === 'AbortError') { self.onDegrade('PBL_E_TIMEOUT', '契约超时 ' + name); }
+      else if (err && !err.code) { self.onDegrade('PBL_E_NETWORK', '网络中断'); }
+      throw err;
+    });
+  };
+
+  /* ───────────── 2. S1 进入世界：一次 bootstrap 拿齐上下文 ───────────── */
+  Transport.prototype.bootstrap = function (extra) {
+    var self = this;
+    return this.call('bootstrap', Object.assign({ recent_events: 20 }, extra || {})).then(function (ctx) {
+      var d = (ctx && ctx.data) || ctx || {};
+      self.context = d;
+      if (Array.isArray(d.recent_events)) {
+        d.recent_events.forEach(function (ev) { self._accept(ev, true); });
+      }
+      if (d.max_seq !== undefined) { self.lastSeq = Math.max(self.lastSeq, Number(d.max_seq) || 0); }
+      return d;
+    });
+  };
+
+  Transport.prototype.pageRegistry = function () {
+    return this.call('page_registry', { page_size: 50 }).then(function (r) {
+      var d = (r && r.data) || r || {};
+      return d.rows || d.data || d || [];
+    });
+  };
+
+  /* ───────────── 3. S2 意图上行（前端无权威状态，仅发起） ───────────── */
+  Transport.prototype.submitIntent = function (intent) {
+    var payload = {
+      intent_type: intent.type || 'action',
+      action: intent.action || '',
+      entity_id: intent.entity_id || '',
+      payload_json: JSON.stringify(intent.payload || {}),
+      client_ts: Date.now()
+    };
+    var self = this;
+    Core.Bus.emit('pbl:intent-submitted', payload);
+    return this.call(intent.channel || 'submit_intent', payload).then(function (r) {
+      var d = (r && r.data) || r || {};
+      // 服务端权威：只有回传 seq 后才允许更新覆盖层（不预测渲染）
+      if (d.seq !== undefined) { self._accept({ seq: d.seq, event_type: intent.action || 'ack', payload_json: d }, true); }
+      return d;
+    });
+  };
+
+  /* ───────────── 4. 广播通道：SSE 优先，长轮询降级 ───────────── */
+  Transport.prototype.subscribe = function () {
+    var self = this;
+    if (this.stopped) { return; }
+    var sseUrl = apiBase() + '/pbl_runtime_ext/api/pbl_runtime_broadcast_pull.dspy?session_id=' +
+                 encodeURIComponent(this.sessionId || '') + '&since_seq=' + this.lastSeq;
+    var ok = false;
+    if (typeof global.EventSource === 'function' && !this.sse) {
+      try {
+        this.sse = new global.EventSource(sseUrl);
+        this.sse.onmessage = function (m) {
+          var ev = null;
+          try { ev = JSON.parse(m.data); } catch (e) { ev = null; }
+          if (ev) { self._accept(ev); }
+        };
+        this.sse.onerror = function () {
+          self.closeSse();
+          self.onDegrade('PBL_RENDER_DEGRADED', '实时通道降级为长轮询');
+          self.poll();
+        };
+        ok = true;
+      } catch (e) { ok = false; }
+    }
+    if (!ok) { this.poll(); }
+  };
+
+  Transport.prototype.closeSse = function () {
+    if (this.sse) { try { this.sse.close(); } catch (e) { } this.sse = null; }
+  };
+
+  /** 长轮询降级：固定节拍拉取增量（seq 单调，去重幂等） */
+  Transport.prototype.poll = function () {
+    var self = this;
+    if (this.stopped) { return; }
+    if (this.timer) { clearInterval(this.timer); }
+    this.timer = setInterval(function () { self.pollOnce(); }, BUDGETS.poll_interval_ms);
+    this.pollOnce();
+  };
+
+  Transport.prototype.pollOnce = function () {
+    var self = this;
+    return this.call('broadcast_pull', { since_seq: this.lastSeq, limit: 50 })
+      .then(function (r) {
+        var d = (r && r.data) || r || {};
+        var evs = d.events || d.rows || [];
+        for (var i = 0; i < evs.length; i++) { self._accept(evs[i]); }
+        if (d.max_seq !== undefined) { self.lastSeq = Math.max(self.lastSeq, Number(d.max_seq) || 0); }
+      })
+      .catch(function () { self.onDegrade('PBL_E_NETWORK', '广播拉取失败，使用缓存数据'); });
+  };
+
+  /** seq 去重 + 计时（广播到达 → 交给上层渲染，≤500ms 预算） */
+  Transport.prototype._accept = function (ev, silent) {
+    if (!ev) { return false; }
+    var seq = Number(ev.seq !== undefined ? ev.seq : (ev.event_seq || 0));
+    if (seq > 0) {
+      if (seq <= this.lastSeq || this.pending[seq]) { return false; }
+      this.pending[seq] = true;
+      this.lastSeq = Math.max(this.lastSeq, seq);
+    }
+    var payload = ev.payload_json;
+    if (typeof payload === 'string') { try { payload = JSON.parse(payload); } catch (e) { payload = { raw: payload }; } }
+    var item = {
+      seq: seq,
+      event_type: ev.event_type || ev.type || 'unknown',
+      entity_id: ev.entity_id || (payload && payload.entity_id) || '',
+      payload: payload || {},
+      received_at: Core.now()
+    };
+    if (!silent) { Core.Bus.emit('pbl:broadcast-received', item); }
+    this.onEvent(item, !!silent);
+    return true;
+  };
+
+  /* ───────────── 5. 断线重连补齐（Q4：快照 + since 补发） ───────────── */
+  Transport.prototype.reconnect = function () {
+    var self = this;
+    return this.call('entity_state', { session_id: this.sessionId })
+      .then(function (r) {
+        var d = (r && r.data) || r || {};
+        self.snapshot = d;
+        Core.Bus.emit('pbl:snapshot-applied', d);
+        return self.call('event_poll', { since_event_id: self.lastSeq, limit: 100 });
+      })
+      .then(function (r) {
+        var d = (r && r.data) || r || {};
+        (d.events || d.rows || []).forEach(function (ev) { self._accept(ev); });
+        self.subscribe();
+        return true;
+      })
+      .catch(function () { self.onDegrade('PBL_E_NETWORK', '重连失败，保持只读缓存'); return false; });
+  };
+
+  /* ───────────── 6. S3/S4 产出物、证据、反馈 ───────────── */
+  Transport.prototype.createArtifact = function (a) {
+    return this.call('artifact_create', {
+      title: a.title || '', artifact_type: a.artifact_type || 'document',
+      content_txt: a.content_txt || '', session_id: this.sessionId
+    });
+  };
+  Transport.prototype.submitArtifact = function (artifactId) {
+    return this.call('artifact_submit', { artifact_id: artifactId, session_id: this.sessionId });
+  };
+  Transport.prototype.collectEvidence = function (e) {
+    return this.call('evidence_collect', {
+      evidence_type: e.evidence_type || 'artifact_version',
+      source_id: e.source_id || '', session_id: this.sessionId
+    });
+  };
+  Transport.prototype.saveFeedback = function (f) {
+    return this.call('feedback_save', {
+      feedback_type: f.feedback_type || 'feedback',
+      rating: f.rating === undefined ? '' : f.rating,
+      content_txt: f.content_txt || '',
+      context_json: f.context_json || {}
+    });
+  };
+
+  Transport.prototype.stop = function () {
+    this.stopped = true;
+    this.closeSse();
+    if (this.timer) { clearInterval(this.timer); this.timer = null; }
+  };
+
+  global.PblOverlayTransport = {
+    ENDPOINTS: ENDPOINTS,
+    apiBase: apiBase,
+    Transport: Transport
+  };
+})(window);