优化: UI/UX遗留批(审计/AI命令层/前端组件,会话前基线收尾)

- AuditLog +298(筛选/详情/i18n)+ audit 后端 record/mod

- AI 命令层:generate_image +81 / fetch_url / fetch_search / skills / tool_registry / tools/file / provider / conversation

- 前端组件:AiChat/TopBar/ConversationSidebar/GitChanges/ApprovalPopup/Dashboard/ProjectDetail 等 30+ + composables + i18n

- 诊断文档: aichat历史会话实证诊断-2026-08-04 + project_soft_delete 测试

src/i18n/en/nav.ts

@@ -5,7 +5,7 @@ export default {
     projects: 'Projects',
     tasks: 'Tasks',
     knowledge: 'Knowledge',
-    audit: 'Audit Log',
+    audit: 'History',
     settings: 'Settings',
     workspace: 'Workspace',
     traceability: 'Traceability',