fix: 全面审计修复 — P0 功能缺陷 + P1 代码质量

P0 功能修复:
- stats: Admin V2 仪表盘 API 路径修正 (/stats/dashboard → /admin/dashboard)
- mcp: 桌面端 MCP 插件增加 isTauriRuntime() 守卫，避免浏览器模式崩溃
- admin: 侧边栏高亮逻辑修复 (startsWith → 精确匹配+子路径)

P1 代码质量:
- 删除 workflowBuilderStore.ts 死代码 (456行，零引用)
- sqlite.rs 3 处 SQL 静默失败改为 tracing::warn! 日志
- mcp_tool_adapter 2 处 unwrap 改为安全回退
- orchestration_execute 添加 @reserved 标注
- TRUTH.md 测试数字校准 (734→803)，Store 数 26→25

desktop/src-tauri/src/kernel_commands/orchestration.rs

@@ -204,6 +204,7 @@ impl From<zclaw_skills::orchestration::OrchestrationResult> for OrchestrationRes
 
 /// @reserved — no frontend UI yet
 /// Execute a skill orchestration
+/// @reserved — orchestration engine internal, no direct frontend caller
 ///
 /// Either auto-composes a graph from skill_ids, or uses a pre-defined graph.
 /// Executes with true parallel execution within each dependency level.