feat(api): drive CORS + trusted origins from CORS_ORIGINS env

Phone/LAN testing previously required editing both app.ts (cors origin) and
auth.ts (better-auth trustedOrigins). Now both read env.WEB_ORIGINS, parsed from
a comma-separated CORS_ORIGINS env var (default http://localhost:5173). To test
from a phone, set CORS_ORIGINS to include the LAN origin and restart the API — no
code edit. Documented in .env.example. Also fixed the worker README (db:migrate
creates ./data/app.db, not ./.tmp; phone step now uses CORS_ORIGINS). API tests
36/36 green; typecheck clean.

apps/api/src/app.ts

@@ -5,13 +5,14 @@ import { me } from './routes/me';
 import { activitiesRoutes } from './routes/activities';
 import { sessionsRoutes } from './routes/sessions';
 import { auth } from './auth';
+import { env } from './env';
 
 export function createApp(): Hono {
   const app = new Hono();
   app.use(
     '/api/*',
     cors({
-      origin: ['http://localhost:5173'],
+      origin: env.WEB_ORIGINS,
       allowMethods: ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'],
       allowHeaders: ['Content-Type', 'Authorization'],
       exposeHeaders: ['set-auth-token'], // so the SPA can read the bearer token on sign-in

apps/api/src/auth.ts

@@ -8,7 +8,7 @@ import { env } from './env';
 export const auth = betterAuth({
   secret: env.BETTER_AUTH_SECRET,
   baseURL: env.BETTER_AUTH_URL,
-  trustedOrigins: [env.BETTER_AUTH_URL, 'http://localhost:3000', 'http://localhost:5173'],
+  trustedOrigins: [env.BETTER_AUTH_URL, 'http://localhost:3000', ...env.WEB_ORIGINS],
   database: drizzleAdapter(db, { provider: 'sqlite', schema }),
   emailAndPassword: {
     enabled: true,

apps/api/src/env.ts

@@ -1,6 +1,14 @@
+const webOrigins = process.env.CORS_ORIGINS?.split(',')
+  .map((s) => s.trim())
+  .filter(Boolean);
+
 export const env = {
   DATABASE_URL: process.env.DATABASE_URL ?? 'file:./data/app.db',
   BETTER_AUTH_SECRET: process.env.BETTER_AUTH_SECRET ?? 'dev-insecure-secret-change-me',
   BETTER_AUTH_URL: process.env.BETTER_AUTH_URL ?? 'http://localhost:3000',
   PORT: Number(process.env.PORT ?? 3000),
+  // Browser origins allowed for CORS + better-auth trustedOrigins. Set CORS_ORIGINS to a
+  // comma-separated list (e.g. "http://localhost:5173,http://192.168.1.50:5173") to let a
+  // phone on the LAN reach the API — no code edit needed. Defaults to the local Vite origin.
+  WEB_ORIGINS: webOrigins && webOrigins.length ? webOrigins : ['http://localhost:5173'],
 };