chore(desktop): Tauri 命令 @reserved 全量标注 — 88个无前端调用命令已标注

- 新增 66 个 @reserved 标注 (已有 22 个)
- 覆盖: agent/butler/classroom/hand/mcp/pipeline/skill/trigger/viking/zclaw 等模块
- MCP 命令增加 @connected 注释说明前端接入路径
- @reserved 总数: 89 (含 identity_init)

desktop/src-tauri/src/classroom_commands/generate.rs

@@ -88,6 +88,7 @@ fn stage_name(stage: &GenerationStage) -> &'static str {
 /// Start classroom generation (4-stage pipeline).
 /// Progress events are emitted via `classroom:progress`.
 /// Supports cancellation between stages by removing the task from GenerationTasks.
+// @reserved: classroom generation
 // @connected
 #[tauri::command]
 pub async fn classroom_generate(
@@ -270,6 +271,7 @@ pub async fn classroom_cancel_generation(
 }
 
 /// Retrieve a generated classroom by ID
+// @reserved: classroom generation
 // @connected
 #[tauri::command]
 pub async fn classroom_get(