debug: add detailed error logging for trainers fetch

- Add console logs to debug Supabase connection
- Improve error message handling for non-Error objects
- Add client-side logging for Supabase configuration

admin-web/app/trainers/page.tsx

@@ -23,12 +23,26 @@ export default function TrainersPage() {
   const fetchTrainers = async () => {
     try {
       setError(null);
+      console.log("Fetching trainers...");
+      
       const { data, error } = await supabase.from("trainers").select("*").order("name");
-      if (error) throw error;
+      
+      console.log("Supabase response:", { data, error });
+      
+      if (error) {
+        console.error("Supabase error:", error);
+        throw new Error(error.message || "Database error");
+      }
+      
       setTrainers(data || []);
     } catch (err) {
       console.error("Failed to fetch trainers:", err);
-      setError(err instanceof Error ? err.message : "Failed to connect to database");
+      const errorMessage = err instanceof Error 
+        ? err.message 
+        : typeof err === 'object' && err !== null
+          ? JSON.stringify(err)
+          : "Failed to connect to database";
+      setError(errorMessage);
     } finally {
       setLoading(false);
     }