Update .gitignore and mask 'secret' in settings API

Added /cache, /redis, and /pgdata to .gitignore to prevent committing local data directories. Updated the admin settings API to also mask values for keys containing 'secret' in addition to other sensitive keys.

.gitignore

@@ -48,4 +48,7 @@ next-env.d.ts
 /media
 
 /src/generated/prisma
-/RMAB
+/RMAB
+/cache
+/redis
+/pgdata

src/app/api/admin/settings/route.ts

@@ -17,7 +17,7 @@ export async function GET(request: NextRequest) {
 
     // Mask sensitive values
     const maskValue = (key: string, value: string | null | undefined) => {
-      const sensitiveKeys = ['token', 'api_key', 'password'];
+      const sensitiveKeys = ['token', 'api_key', 'password', 'secret'];
       if (value && sensitiveKeys.some((k) => key.includes(k))) {
         return '••••••••••••';
       }