feat: wire Sentry, conditional on DSN env var

apps/web (@sentry/nextjs):
- sentry.client.config.ts / sentry.server.config.ts / sentry.edge.config.ts
  initialize Sentry only when NEXT_PUBLIC_SENTRY_DSN (or SENTRY_DSN on the
  server) is set; tracesSampleRate 0.1
- next.config.mjs wraps the existing config with withSentryConfig only when a
  DSN is present; source-map upload stays disabled until SENTRY_AUTH_TOKEN is
  provided
- .env.example documents NEXT_PUBLIC_SENTRY_DSN and the optional auth token

apps/api (@sentry/node):
- src/lib/sentry.ts initializes Sentry at module load when SENTRY_DSN is set
- server.ts imports sentry.ts as the very first side-effect so early-boot
  errors (env validation, plugin registration) reach Sentry
- env schema gains optional SENTRY_DSN (URL)
- app.ts registers an errorHandler that captures the exception with the
  authenticated user when SENTRY_DSN is set; logs and re-sends as before

Build-time housekeeping:
- profile route: targetDate ?? null on create to satisfy Prisma's input shape
  under exactOptionalPropertyTypes
- profile form: useForm receives defaultValues only when initial is provided
  (spread instead of `defaultValues: undefined`); Field error prop typed
  `string | undefined` for exactOptionalPropertyTypes

Without a DSN both apps run unchanged (Sentry is inert).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/api/.env.example

@@ -15,3 +15,6 @@ BETTER_AUTH_URL=http://localhost:3000
 # Google OAuth (configurato a fine progetto)
 # GOOGLE_CLIENT_ID=
 # GOOGLE_CLIENT_SECRET=
+
+# Sentry — error tracking (lascia vuoto per disabilitare)
+# SENTRY_DSN=

apps/api/package.json

@@ -18,6 +18,7 @@
     "@ketopath/auth": "workspace:*",
     "@ketopath/db": "workspace:*",
     "@ketopath/shared": "workspace:*",
+    "@sentry/node": "^8.30.0",
     "better-auth": "^1.0.21",
     "fastify": "^4.28.1",
     "fastify-plugin": "^4.5.1",

apps/api/src/app.ts

@@ -5,6 +5,7 @@ import sensible from '@fastify/sensible';
 import Fastify, { type FastifyInstance } from 'fastify';
 
 import { env } from './config/env.js';
+import { Sentry } from './lib/sentry.js';
 import { dbRoutes } from './modules/db/db.routes.js';
 import { healthRoutes } from './modules/health/health.routes.js';
 import { meRoutes } from './modules/me/me.routes.js';
@@ -46,5 +47,19 @@ export async function buildApp(): Promise<FastifyInstance> {
   await app.register(meRoutes);
   await app.register(profileRoutes);
 
+  if (env.SENTRY_DSN) {
+    app.setErrorHandler((err, request, reply) => {
+      if (request.user) {
+        Sentry.captureException(err, {
+          user: { id: request.user.id, email: request.user.email },
+        });
+      } else {
+        Sentry.captureException(err);
+      }
+      app.log.error({ err }, 'unhandled error');
+      reply.send(err);
+    });
+  }
+
   return app;
 }

apps/api/src/config/env.ts

@@ -17,6 +17,7 @@ const envSchema = z.object({
   DATABASE_URL: z.string().url(),
   BETTER_AUTH_SECRET: z.string().min(32),
   BETTER_AUTH_URL: z.string().url(),
+  SENTRY_DSN: z.string().url().optional(),
 });
 
 export type Env = z.infer<typeof envSchema>;

apps/api/src/lib/sentry.ts

@@ -0,0 +1,13 @@
+import * as Sentry from '@sentry/node';
+
+import { env } from '../config/env.js';
+
+if (env.SENTRY_DSN) {
+  Sentry.init({
+    dsn: env.SENTRY_DSN,
+    environment: env.NODE_ENV,
+    tracesSampleRate: 0.1,
+  });
+}
+
+export { Sentry };

apps/api/src/modules/profile/profile.routes.ts

@@ -78,7 +78,7 @@ export const profileRoutes: FastifyPluginAsync = async (fastify) => {
         weightCurrentKg: data.weightCurrentKg,
         weightGoalKg: data.weightGoalKg,
         activityLevel: data.activityLevel,
-        targetDate: data.targetDate,
+        targetDate: data.targetDate ?? null,
       },
       update: {
         age: data.age,

apps/api/src/server.ts

@@ -1,3 +1,7 @@
+// Side-effect import: initializes Sentry before any other module is evaluated.
+// Must stay first — moving it later means errors thrown during early boot
+// (env validation, Prisma adapter, etc.) wouldn't reach Sentry.
+import './lib/sentry.js';
 import { buildApp } from './app.js';
 import { env } from './config/env.js';