v0.11.11: 彻底移除技能系统，工具 44→42，SQLite 7→6 张表

- 删除 src/renderer/services/skill-manager.ts (480行)
- sqlite.ts: 删除 skills 表/索引/迁移/SkillRow接口/CRUD
- ipc.ts: 删除 6 个 skills IPC handler
- preload.ts/types.d.ts: 删除 skills bridge 方法/类型
- agent-engine.ts: 删除技能匹配上下文注入/自动提取
- tool-registry.ts: 删除 skill_list/skill_view 工具定义/执行
- log-service.ts/sub-agent.ts/workspace-panel.ts: 清理引用
- index.html: 帮助面板/工具卡片更新，44→42
- README/release-notes/DEVELOPMENT/AGENT: 文档全量同步

src/main/ipc.ts

@@ -15,7 +15,6 @@ import {
   saveSetting, getSetting,
   saveToolCall, getToolCallsBySession,
   saveTrace, getTracesBySession,
-  saveSkill, getAllSkills, deleteSkill, clearAllSkills, searchSkills, incrementSkillUsage,
   exportAllSessions, importSessions,
   getAllSessionsTokenStats
 } from './db/sqlite.js';
@@ -433,32 +432,6 @@ export async function setupIPC(): Promise<void> {
     catch (err) { sendLog('error', '导入失败', (err as Error).message); return { imported: 0, skipped: 0 }; }
   });
 
-  // ── Skills (v4.2) ──
-  ipcMain.handle('db:saveSkill', (_, skill) => {
-    try { return { success: true, id: saveSkill(skill) }; }
-    catch (err) { return { success: false, error: (err as Error).message }; }
-  });
-  ipcMain.handle('db:getAllSkills', () => {
-    try { return getAllSkills(); }
-    catch { return []; }
-  });
-  ipcMain.handle('db:deleteSkill', (_, id) => {
-    try { deleteSkill(id); return { success: true }; }
-    catch (err) { return { success: false, error: (err as Error).message }; }
-  });
-  ipcMain.handle('db:clearAllSkills', () => {
-    try { clearAllSkills(); return { success: true }; }
-    catch (err) { return { success: false, error: (err as Error).message }; }
-  });
-  ipcMain.handle('db:searchSkills', (_, query: string, limit?: number) => {
-    try { return searchSkills(query, limit ?? 5); }
-    catch { return []; }
-  });
-  ipcMain.handle('db:incrementSkillUsage', (_, id: string, success: boolean, durationMs: number) => {
-    try { incrementSkillUsage(id, success, durationMs); return { success: true }; }
-    catch (err) { return { success: false, error: (err as Error).message }; }
-  });
-
   // ── Token 全局统计 ──
   ipcMain.handle('db:getAllTokenStats', () => {
     try { return getAllSessionsTokenStats(); }