fix: use POSTGRES_PASSWORD from secret instead of hardcoded value

chart/templates/backend-migration.job.yaml

@@ -19,7 +19,7 @@ spec:
               echo "=== Environment Variables ==="
               env | grep -i postgres
               echo "=== Testing Connection ==="
-              PGPASSWORD=A0Sz0FnNSOmk1fbnotF6kb4UKu4nDezKu608 psql -h postgres-service -p 5432 -U prod_admin -d fusero-db -c "SELECT 1"
+              PGPASSWORD=$POSTGRES_PASSWORD psql "postgresql://$POSTGRES_USER@$POSTGRES_HOSTNAME:$POSTGRES_PORT/$POSTGRES_NAME" -c "SELECT 1"
               echo "=== Running Migrations ==="
               npx mikro-orm migration:up
               echo "=== Running Seeds ==="
@@ -29,12 +29,17 @@ spec:
               value: "postgres-service"
             - name: POSTGRES_PORT
               value: "5432"
-            - name: POSTGRES_DB
+            - name: POSTGRES_NAME
               value: "fusero-db"
             - name: POSTGRES_USER
               value: "prod_admin"
             - name: POSTGRES_PASSWORD
-              value: "A0Sz0FnNSOmk1fbnotF6kb4UKu4nDezKu608"
+              valueFrom:
+                secretKeyRef:
+                  name: fusero-backend-secrets
+                  key: POSTGRES_PASSWORD
+            - name: NODE_ENV
+              value: "production"
             - name: DEFAULT_ADMIN_USERNAME
               value: "{{ .Values.backend.env.DEFAULT_ADMIN_USERNAME }}"
             - name: DEFAULT_ADMIN_EMAIL