feat(MCN工作台): 数据功能页+图标扁平化+多项UI优化

- 工作台大版本升级：hash 路由 + 6 数据功能页（周榜/热门账号/账号详情/视频详情/AI写脚本/AI写作复盘），只读复用 dsh 库副本 + 抖音榜单 JSON
- 数据库隔离：复制 dsh 库到 mcn-work-shop/，与 dsh 原库各访问各的（已 gitignore）
- 图标全面扁平化：Lucide 线性 SVG，功能图标亮色区分，文字标题去图标
- 首页重构：功能入口卡 + AI写剧本快捷卡片(2列/8个/5行预览) + 独立帮助页 + header 精简
- 新增设计技能 impeccable + taste-skill（生成网页时参考）
- 修复：fmtTime 跨 script 全局冲突(P0)、弹窗关闭、外链新标签打开等

.workbuddy/skills/impeccable/scripts/live-browser-session.js

@@ -0,0 +1,123 @@
+/**
+ * Browser-side durable session helpers for Impeccable live mode.
+ *
+ * Kept separate from live-browser.js so recovery state can be tested without
+ * booting the full overlay UI. Served before live-browser.js and attached to
+ * window.__IMPECCABLE_LIVE_SESSION__.
+ */
+(function (root) {
+  'use strict';
+
+  function createLiveBrowserSessionState({ prefix, storage, idFactory }) {
+    if (!prefix) throw new Error('prefix required');
+    const store = storage || root.localStorage;
+    const makeId = idFactory || function () { return Math.random().toString(16).slice(2, 10); };
+    const sessionKey = prefix + '-session';
+    const handledKey = sessionKey + '-handled';
+    const scrollKey = sessionKey + '-scroll';
+    let checkpointRevision = 0;
+    const owner = makeId();
+
+    function safeRead(key) {
+      try { return store.getItem(key); } catch { return null; }
+    }
+
+    function safeWrite(key, value) {
+      try { store.setItem(key, value); } catch { /* quota exceeded or private mode */ }
+    }
+
+    function safeRemove(key) {
+      try { store.removeItem(key); } catch { /* unavailable storage */ }
+    }
+
+    function loadSession() {
+      try {
+        const raw = safeRead(sessionKey);
+        if (!raw) return null;
+        const parsed = JSON.parse(raw);
+        if (Number.isInteger(parsed.checkpointRevision)) {
+          checkpointRevision = Math.max(checkpointRevision, parsed.checkpointRevision);
+        }
+        return parsed;
+      } catch { return null; }
+    }
+
+    function saveSession(session) {
+      if (!session || !session.id) return;
+      const payload = {
+        ...session,
+        checkpointRevision,
+      };
+      safeWrite(sessionKey, JSON.stringify(payload));
+    }
+
+    function clearSession() {
+      safeRemove(sessionKey);
+    }
+
+    function nextCheckpointRevision() {
+      checkpointRevision += 1;
+      const existing = loadSession();
+      if (existing?.id) saveSession(existing);
+      return checkpointRevision;
+    }
+
+    function seedCheckpointRevision(value) {
+      if (Number.isInteger(value)) checkpointRevision = Math.max(checkpointRevision, value);
+      return checkpointRevision;
+    }
+
+    function currentCheckpointRevision() {
+      return checkpointRevision;
+    }
+
+    function markHandled(id) {
+      if (!id) return;
+      safeWrite(handledKey, id);
+    }
+
+    function isHandled(id) {
+      return !!id && safeRead(handledKey) === id;
+    }
+
+    function clearHandled() {
+      safeRemove(handledKey);
+    }
+
+    function writeScrollY(y) {
+      safeWrite(scrollKey, String(y));
+    }
+
+    function readScrollY() {
+      const raw = safeRead(scrollKey);
+      if (raw == null) return null;
+      const n = parseFloat(raw);
+      return isFinite(n) ? n : null;
+    }
+
+    function clearScrollY() {
+      safeRemove(scrollKey);
+    }
+
+    return {
+      owner,
+      sessionKey,
+      handledKey,
+      scrollKey,
+      saveSession,
+      loadSession,
+      clearSession,
+      nextCheckpointRevision,
+      seedCheckpointRevision,
+      currentCheckpointRevision,
+      markHandled,
+      isHandled,
+      clearHandled,
+      writeScrollY,
+      readScrollY,
+      clearScrollY,
+    };
+  }
+
+  root.__IMPECCABLE_LIVE_SESSION__ = { createLiveBrowserSessionState };
+})(typeof window !== 'undefined' ? window : globalThis);