Fix foreign key constraint error when creating proxy hosts

The issue occurred because the auth system uses a hardcoded JWT user ID (1)
that didn't exist in the database, causing foreign key constraint violations
when creating proxy hosts.

Changes:
- Added init-db.ts to ensure admin user exists in database
- Added instrumentation.ts to run DB initialization on server startup
- Admin user (from ADMIN_USERNAME env var) is now created with ID 1
- Matches the hardcoded ID in auth.ts for JWT tokens

Fixes foreign key constraint error (P2003) when creating proxy hosts.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

next-env.d.ts

@@ -1,6 +1,6 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
-import "./.next/dev/types/routes.d.ts";
+import "./.next/types/routes.d.ts";
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.

src/instrumentation.ts

@@ -0,0 +1,18 @@
+/**
+ * Next.js instrumentation hook - runs once when the server starts
+ * https://nextjs.org/docs/app/building-your-application/optimizing/instrumentation
+ */
+export async function register() {
+  // Only run on the server side
+  if (process.env.NEXT_RUNTIME === "nodejs") {
+    const { ensureAdminUser } = await import("./lib/init-db");
+
+    try {
+      await ensureAdminUser();
+      console.log("Database initialization complete");
+    } catch (error) {
+      console.error("Failed to initialize database:", error);
+      // Don't throw - let the app start anyway, errors will surface when users try to use features
+    }
+  }
+}

src/lib/init-db.ts

@@ -0,0 +1,55 @@
+import prisma, { nowIso } from "./db";
+import { config } from "./config";
+
+/**
+ * Ensures the admin user from environment variables exists in the database.
+ * This is called during application startup.
+ */
+export async function ensureAdminUser(): Promise<void> {
+  const adminId = 1; // Must match the hardcoded ID in auth.ts
+  const adminEmail = `${config.adminUsername}@localhost`;
+  const provider = "credentials";
+  const subject = config.adminUsername;
+
+  // Check if admin user already exists
+  const existingUser = await prisma.user.findUnique({
+    where: { id: adminId }
+  });
+
+  if (existingUser) {
+    // Admin user exists, update if needed
+    if (existingUser.email !== adminEmail || existingUser.subject !== subject) {
+      const now = new Date(nowIso());
+      await prisma.user.update({
+        where: { id: adminId },
+        data: {
+          email: adminEmail,
+          subject,
+          updatedAt: now
+        }
+      });
+      console.log(`Updated admin user: ${config.adminUsername}`);
+    }
+    return;
+  }
+
+  // Create admin user
+  const now = new Date(nowIso());
+  await prisma.user.create({
+    data: {
+      id: adminId,
+      email: adminEmail,
+      name: config.adminUsername,
+      passwordHash: null, // Using environment variable auth, not password hash
+      role: "admin",
+      provider,
+      subject,
+      avatarUrl: null,
+      status: "active",
+      createdAt: now,
+      updatedAt: now
+    }
+  });
+
+  console.log(`Created admin user: ${config.adminUsername}`);
+}