Fix docker-compose: lockfile name, lazy Resend init

Dockerfile

@@ -3,7 +3,7 @@ WORKDIR /app
 
 # Install dependencies
 FROM base AS install
-COPY package.json bun.lockb ./
+COPY package.json bun.lock ./
 RUN bun install --frozen-lockfile --production
 
 # Production image

src/services/email.ts

@@ -1,6 +1,17 @@
 import { Resend } from 'resend';
 
-const resend = new Resend(process.env.RESEND_API_KEY);
+let resend: Resend | null = null;
+
+function getResendClient(): Resend {
+  if (!resend) {
+    const apiKey = process.env.RESEND_API_KEY;
+    if (!apiKey) {
+      throw new Error('RESEND_API_KEY is not configured');
+    }
+    resend = new Resend(apiKey);
+  }
+  return resend;
+}
 
 export interface SendEmailParams {
   to: string;
@@ -11,7 +22,8 @@ export interface SendEmailParams {
 }
 
 export async function sendEmail(params: SendEmailParams) {
-  const { data, error } = await resend.emails.send({
+  const client = getResendClient();
+  const { data, error } = await client.emails.send({
     from: params.from || process.env.DEFAULT_FROM_EMAIL || 'onboarding@resend.dev',
     to: params.to,
     subject: params.subject,