feat: add invite code system and multi-image Drone pipeline

- Add InviteCode model with code, maxUses, expiry, usage tracking
- Registration now requires a valid invite code
- New users get USER role instead of ADMIN
- Admin-only /invites page to create, manage, and share invite codes
- Invite links auto-fill code via ?code= URL param
- Drone pipeline now builds app, worker, and bot images separately
- Add NEXT_PUBLIC_APP_URL build arg to fix URL redirects

src/app/(auth)/register/actions.ts

@@ -11,6 +11,23 @@ export async function registerUser(input: unknown): Promise<ActionResult<{ id: s
     return { success: false, error: "Validation failed" };
   }
 
+  // Validate invite code
+  const invite = await prisma.inviteCode.findUnique({
+    where: { code: parsed.data.inviteCode },
+  });
+
+  if (!invite) {
+    return { success: false, error: "Invalid invite code" };
+  }
+
+  if (invite.uses >= invite.maxUses) {
+    return { success: false, error: "This invite code has already been used" };
+  }
+
+  if (invite.expiresAt && invite.expiresAt < new Date()) {
+    return { success: false, error: "This invite code has expired" };
+  }
+
   const existing = await prisma.user.findUnique({
     where: { email: parsed.data.email },
   });
@@ -21,22 +38,31 @@ export async function registerUser(input: unknown): Promise<ActionResult<{ id: s
 
   const hashedPassword = await bcrypt.hash(parsed.data.password, 10);
 
-  // Self-hosted: all users are admins
-  const user = await prisma.user.create({
-    data: {
-      name: parsed.data.name,
-      email: parsed.data.email,
-      hashedPassword,
-      role: "ADMIN",
-      settings: {
-        create: {
-          lowStockThreshold: 10,
-          currency: "USD",
-          theme: "dark",
-          units: "metric",
+  // Create user and increment invite usage in a transaction
+  const user = await prisma.$transaction(async (tx) => {
+    const newUser = await tx.user.create({
+      data: {
+        name: parsed.data.name,
+        email: parsed.data.email,
+        hashedPassword,
+        role: "USER",
+        settings: {
+          create: {
+            lowStockThreshold: 10,
+            currency: "USD",
+            theme: "dark",
+            units: "metric",
+          },
         },
       },
-    },
+    });
+
+    await tx.inviteCode.update({
+      where: { id: invite.id },
+      data: { uses: { increment: 1 } },
+    });
+
+    return newUser;
   });
 
   return { success: true, data: { id: user.id } };