Fix Prisma 7 client instantiation

In Prisma 7, connection URL is managed via prisma.config.ts.
PrismaClient constructor no longer accepts log options directly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/prisma.ts

@@ -4,10 +4,7 @@ const globalForPrisma = globalThis as unknown as {
   prisma: PrismaClient | undefined;
 };
 
-export const prisma =
+// In Prisma 7, connection is configured via prisma.config.ts, not in constructor
-  globalForPrisma.prisma ??
+export const prisma = globalForPrisma.prisma ?? new PrismaClient();
-  new PrismaClient({
-    log: process.env.NODE_ENV === "development" ? ["error", "warn"] : ["error"],
-  });
 
 if (process.env.NODE_ENV !== "production") globalForPrisma.prisma = prisma;