fix: TicketCreatePage 去掉优先级选择器+修复Redis实例切换后database残留触发MySQL tables请求

frontend/src/pages/TicketCreatePage.tsx

@@ -222,19 +222,24 @@ export default function TicketCreatePage() {
 
   useEffect(() => {
     if (!instanceId) { setDatabases([]); setDatabase(''); return; }
+    // 立即重置，避免旧 database 残留触发 tables 请求
+    setDatabase('');
+    setDatabases([]);
+    setTables([]);
     const inst = instances.find(i => i.id === Number(instanceId));
+    if (inst?.db_type === 'redis') {
+      setDatabase('db0');
+      setDatabases(['db0']);
+      return;
+    }
     setLoadingDatabases(true);
     instanceApi.listDatabases(Number(instanceId))
       .then((res: unknown) => {
         const data = (res as { databases?: string[] })?.databases || (res as string[]) || [];
         setDatabases(Array.isArray(data) ? data as string[] : []);
         if (Array.isArray(data) && data.length > 0) setDatabase(String(data[0]));
-        else if (inst?.db_type === 'redis') setDatabase('db0');
-      })
-      .catch(() => {
-        setDatabases([]);
-        if (inst?.db_type === 'redis') setDatabase('db0');
       })
+      .catch(() => setDatabases([]))
       .finally(() => setLoadingDatabases(false));
   }, [instanceId, instances]);
 
@@ -735,17 +740,6 @@ export default function TicketCreatePage() {
         />
       </div>
 
-      {/* Priority + DB Type */}
-      <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
-        <div>
-          <label className="block text-sm font-medium mb-2">优先级</label>
-          <select value={priority} onChange={(e) => setPriority(e.target.value)}
-            className="w-full px-3 py-2 bg-[var(--dg-bg-primary)] border border-[var(--dg-border)] rounded-lg text-sm focus:outline-none focus:border-blue-500 transition-colors">
-            {PRIORITY_OPTIONS.map((opt) => <option key={opt.value} value={opt.value}>{opt.label}</option>)}
-          </select>
-        </div>
-      </div>
-
       {/* Instance — 直接展示用户变更授权的实例 */}
       <div>
         <label className="block text-sm font-medium mb-2">
@@ -962,10 +956,6 @@ export default function TicketCreatePage() {
               <span className="text-[var(--dg-text-muted)] text-xs">标题</span>
               <p className="font-medium mt-1">{title}</p>
             </div>
-            <div className="p-3 bg-[var(--dg-bg-primary)] rounded-lg">
-              <span className="text-[var(--dg-text-muted)] text-xs">优先级</span>
-              <p className="font-medium mt-1">{priority === 'high' ? '高' : priority === 'medium' ? '中' : '低'}</p>
-            </div>
             <div className="p-3 bg-[var(--dg-bg-primary)] rounded-lg">
               <span className="text-[var(--dg-text-muted)] text-xs">实例</span>
               <div className="flex items-center gap-1.5 mt-1">