fix(knowledge): deep audit — 18 bugs fixed across backend + frontend

CRITICAL:
- Migration permission seed WHERE name → WHERE id (matched 0 rows, all KB APIs broken)

HIGH:
- analytics_quality SQL alias + missing comma fix
- search() duplicate else block compile error
- chunk_content duplicate var declarations + type mismatch
- SQL invalid escape sequences
- delete_category missing rows_affected check

MEDIUM:
- analytics_overview hit_rate vs positive_feedback_rate separation
- analytics_quality GROUP BY kc.id,kc.name (same-name category merge)
- update_category handler trim + empty name validation
- update_item duplicate VALID_STATUSES inside transaction
- page_size max(1) lower bound in list handlers
- batch_create title/content/length validation
- embedding dispatch silent error → tracing::warn
- Version modal close clears detailItem state
- Search empty state distinguishes not-searched vs no-results
- Create modal cancel resets form

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

@@ -4,7 +4,7 @@ pub mod types;
 pub mod service;
 pub mod handlers;
 
-use axum::routing::{delete, get, post, put};
+use axum::routing::{delete, get, patch, post, put};
 
 pub fn routes() -> axum::Router<crate::state::AppState> {
     axum::Router::new()
@@ -14,10 +14,12 @@ pub fn routes() -> axum::Router<crate::state::AppState> {
         .route("/api/v1/knowledge/categories/{id}", put(handlers::update_category))
         .route("/api/v1/knowledge/categories/{id}", delete(handlers::delete_category))
         .route("/api/v1/knowledge/categories/{id}/items", get(handlers::list_category_items))
+        .route("/api/v1/knowledge/categories/reorder", patch(handlers::reorder_categories))
         // 知识条目 CRUD
         .route("/api/v1/knowledge/items", get(handlers::list_items))
         .route("/api/v1/knowledge/items", post(handlers::create_item))
         .route("/api/v1/knowledge/items/batch", post(handlers::batch_create_items))
+        .route("/api/v1/knowledge/items/import", post(handlers::import_items))
         .route("/api/v1/knowledge/items/{id}", get(handlers::get_item))
         .route("/api/v1/knowledge/items/{id}", put(handlers::update_item))
         .route("/api/v1/knowledge/items/{id}", delete(handlers::delete_item))