Add LLM digest setup and share timestamp context

docs/SETUP.md

@@ -14,6 +14,33 @@ Runtime override (for future settings screens):
 AppConfig.overrideBackendBaseUrl('https://staging.example.com');
 ```
 
+## Bugsink Error Tracking
+
+Release builds initialize `sentry_flutter` with the project Bugsink DSN by
+default. Bugsink is Sentry API compatible, so the app uses the normal Sentry
+Flutter SDK.
+
+The default DSN is:
+
+```text
+https://97fb0a56bc35440fba0ba139dc3b1ccc@bugs.zuzo.ch/2
+```
+
+Override metadata at build time when needed:
+
+```bash
+flutter build apk --release \
+  --dart-define=SENTRY_ENVIRONMENT=production \
+  --dart-define=SENTRY_RELEASE=relationship_saver@1.0.0+1
+```
+
+To point a build at a different Sentry-compatible project:
+
+```bash
+flutter build apk --release \
+  --dart-define=SENTRY_DSN=https://public-key@example.com/1
+```
+
 ## Run With Fake Gateway
 
 Use fake gateway for local/offline development: