Fix production build failure: lazy Prisma client initialization

The Prisma client was constructed eagerly at module load, which called
new URL(process.env.DATABASE_URL!) during Next.js 16 "Collect page data".
When DATABASE_URL wasn't in the build environment (production), this threw
TypeError: Invalid URL { input: 'undefined' } and failed the build for
routes like /api/auth/forgot-password.

Use a Proxy to defer client construction until the first property access,
so build-time module evaluation no longer touches DATABASE_URL.

Made-with: Cursor

src/lib/db.ts

@@ -6,8 +6,14 @@ const globalForPrisma = globalThis as unknown as {
   prisma: PrismaClient | undefined;
 };
 
-function createPrismaClient() {
-  const url = new URL(process.env.DATABASE_URL!);
+function createPrismaClient(): PrismaClient {
+  const dbUrl = process.env.DATABASE_URL;
+  if (!dbUrl) {
+    throw new Error(
+      "DATABASE_URL is not set. Prisma client cannot be initialized."
+    );
+  }
+  const url = new URL(dbUrl);
   url.searchParams.delete("sslmode");
   const pool = new pg.Pool({
     connectionString: url.toString(),
@@ -18,6 +24,23 @@ function createPrismaClient() {
   return new PrismaClient({ adapter });
 }
 
-export const prisma = globalForPrisma.prisma ?? createPrismaClient();
+function getPrismaClient(): PrismaClient {
+  if (!globalForPrisma.prisma) {
+    globalForPrisma.prisma = createPrismaClient();
+  }
+  return globalForPrisma.prisma;
+}
 
-if (process.env.NODE_ENV !== "production") globalForPrisma.prisma = prisma;
+// Lazy proxy so that importing `prisma` does NOT construct the client
+// at module load. This lets Next.js collect page data during build even
+// if DATABASE_URL isn't present in the build environment.
+export const prisma = new Proxy({} as PrismaClient, {
+  get(_target, prop, receiver) {
+    const client = getPrismaClient();
+    const value = Reflect.get(client, prop, receiver);
+    return typeof value === "function" ? value.bind(client) : value;
+  },
+  has(_target, prop) {
+    return Reflect.has(getPrismaClient(), prop);
+  },
+}) as PrismaClient;