fix(audit): Batch 7-9 dead_code 标注 + TODO 清理 + 文档同步

Batch 7: dead_code 标注统一 (16 处)
- crates/ 9 处: growth, kernel, pipeline, runtime, saas, skills
- src-tauri/ 7 处: classroom, intelligence, browser, mcp
- 统一格式: #[allow(dead_code)] // @reserved: <原因>

Batch 7+: EvolutionEngine L2/L3 10 个未使用 pub 函数
- 全部标注 @reserved: EvolutionEngine L2/L3, post-release integration

Batch 9: TODO → FUTURE 标记 (4 处)
- html.rs: template-based export
- nl_schedule.rs: LLM-assisted parsing
- knowledge/handlers.rs: category_id from upload
- personality_detector.rs: VikingStorage persistence

Batch 5+: Cargo.lock 更新 (serde_yaml_bw 迁移)

全量测试通过: 719 passed, 0 failed

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

@@ -33,7 +33,7 @@ impl Default for McpManagerState {
 
 impl McpManagerState {
     /// Create with a pre-allocated kernel_adapters Arc for sharing with Kernel.
-    #[allow(dead_code)]
+    #[allow(dead_code)] // @reserved: alternate constructor for shared MCP adapter injection
     pub fn with_shared_adapters(kernel_adapters: Arc<std::sync::RwLock<Vec<McpToolAdapter>>>) -> Self {
         Self {
             manager: Arc::new(Mutex::new(McpServiceManager::new())),