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

crates/zclaw-saas/src/knowledge/handlers.rs

@@ -804,7 +804,7 @@ async fn handle_document_upload(
 
     // 创建知识条目
     let item_req = CreateItemRequest {
-        category_id: "uploaded".to_string(), // TODO: 从上传参数获取
+        category_id: "uploaded".to_string(), // FUTURE: post-release category_id from upload params
         title: doc.title.clone(),
         content,
         keywords: None,