Refactor parseJson to handle different value types

Refactor parseJson function to handle various input types and improve null checks.

src/server/services/downstreamApiKeyService.ts

@@ -90,8 +90,17 @@ function normalizePositiveIntegerOrNull(value: unknown): number | null {
   return normalized;
 }
 
-function parseJson(value: string | null | undefined): unknown {
-  if (!value) return null;
+function parseJson(value: unknown): unknown {
+  if (value === null || value === undefined) return null;
+
+  // PostgreSQL JSONB columns are returned as parsed objects/arrays by the pg driver
+  if (typeof value === 'object') {
+    return value;
+  }
+
+  // SQLite TEXT columns store JSON as strings that need parsing
+  if (typeof value === 'string') {
+    if (value === '') return null;
     try {
       return JSON.parse(value);
     } catch {
@@ -99,6 +108,9 @@ function parseJson(value: string | null | undefined): unknown {
     }
   }
 
+  return null;
+}
+
 export function normalizeGroupNameInput(input: unknown): string | null {
   if (typeof input !== 'string') return null;
   const value = input.trim();