feat: add MindSearch admin controls

src/types.ts

@@ -597,3 +597,10 @@ export type AdminSubscription = {
   note: string | null;
   createdAt: number;
 };
+
+export type MindSearchConfig = {
+  enabled: boolean;
+  mode: 'off' | 'shadow' | 'assist';
+  providers: { searxng: boolean; github: boolean; reader: boolean };
+  settings: { searxngEndpoint: string; maxResults: number; timeoutMs: number; readerMaxChars: number };
+};