fix: resolve remaining clippy warnings and improve workflow frontend

- Collapse nested if-let in user_service.rs search filter
- Suppress dead_code warning on ApiDoc struct
- Refactor server routing: nest all routes under /api/v1 prefix
- Simplify health check route path
- Improve workflow ProcessDesigner with edit mode and loading states
- Update workflow pages with enhanced UX
- Add Phase 2 implementation plan document

crates/erp-server/src/handlers/health.rs

@@ -13,7 +13,7 @@ pub struct HealthResponse {
     pub modules: Vec<String>,
 }
 
-/// GET /api/v1/health
+/// GET /health
 ///
 /// 服务健康检查，返回运行状态和已注册模块列表
 pub async fn health_check(State(state): State<AppState>) -> Json<HealthResponse> {
@@ -32,5 +32,5 @@ pub async fn health_check(State(state): State<AppState>) -> Json<HealthResponse>
 }
 
 pub fn health_check_router() -> Router<AppState> {
-    Router::new().route("/api/v1/health", get(health_check))
+    Router::new().route("/health", get(health_check))
 }