fix(db): check callers against the adapter that actually runs

The self-hosted client was typed as a full Supabase client, so an old scoring poll called .single() on a plain promise and failed. The new DataClient only lists methods the adapter implements.

Co-Authored-By: Grok (agent loop)

frontend/src/app/api/chart-profiles/route.ts

@@ -56,7 +56,7 @@ export async function GET() {
       .order("updated_at", { ascending: false });
 
     if (error) throw error;
-    const profiles = (data ?? []).map((row) => toClientProfile(row as Record<string, unknown>));
+    const profiles = (data ?? []).map((row: unknown) => toClientProfile(row as Record<string, unknown>));
     return NextResponse.json({
       profiles,
       limit: MAX_SAVED_SUBJECTS,