chore(telemetry): add tracing headers to flush + .env.example

web/.env.example

@@ -0,0 +1,5 @@
+# ChronoMind Web — Environment Configuration
+# Copy to .env.local and fill in values
+
+# Platform Service (backend API for sync, auth, telemetry)
+NEXT_PUBLIC_PLATFORM_SERVICE_URL=http://localhost:4003/api

web/.gitignore

@@ -35,6 +35,7 @@ yarn-error.log*
 
 # env files (can opt-in for committing if needed)
 .env*
+!.env.example
 
 # vercel
 .vercel

web/src/lib/telemetry.ts

@@ -121,16 +121,20 @@ export function flush(): void {
   const body = JSON.stringify({ productId: PRODUCT_ID, events });
   const url = `${baseUrl}/telemetry/events`;
 
+  const headers: Record<string, string> = {
+    'Content-Type': 'application/json',
+    'x-product-id': PRODUCT_ID,
+    'x-request-id': uuid(),
+  };
+
   try {
-    const sent = navigator.sendBeacon(url, body);
-    if (!sent) {
-      fetch(url, {
-        method: 'POST',
-        headers: { 'Content-Type': 'application/json' },
-        body,
-        keepalive: true,
-      }).catch(() => {});
-    }
+    // sendBeacon doesn't support custom headers — use fetch with keepalive
+    fetch(url, {
+      method: 'POST',
+      headers,
+      body,
+      keepalive: true,
+    }).catch(() => {});
   } catch {
     // Best effort — telemetry is non-critical
   }