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-auth/src/service/user_service.rs

@@ -136,13 +136,11 @@ impl UserService {
             .filter(user::Column::TenantId.eq(tenant_id))
             .filter(user::Column::DeletedAt.is_null());
 
-        if let Some(term) = search {
-            if !term.is_empty() {
-                use sea_orm::sea_query::Expr;
-                query = query.filter(
-                    Expr::col(user::Column::Username).like(format!("%{}%", term)),
-                );
-            }
+        if let Some(term) = search && !term.is_empty() {
+            use sea_orm::sea_query::Expr;
+            query = query.filter(
+                Expr::col(user::Column::Username).like(format!("%{}%", term)),
+            );
         }
 
         let paginator = query.paginate(db, pagination.limit());