fix(backend): make sentry traces-sample-rate env-configurable

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.env.example

@@ -50,6 +50,7 @@ GLITCHTIP_SECRET_KEY=changeme-generate-a-real-secret
 # Error reporting DSNs — leave empty to disable the SDK (safe default).
 # SENTRY_DSN: backend (Spring Boot) — used by the GlitchTip/Sentry Java SDK
 SENTRY_DSN=
+SENTRY_TRACES_SAMPLE_RATE=
 # VITE_SENTRY_DSN: frontend (SvelteKit) — injected at build time via Vite
 VITE_SENTRY_DSN=
 # Sentry/GlitchTip auth token for source map upload at build time (optional)

backend/pom.xml

@@ -224,6 +224,13 @@
 				</exclusion>
 			</exclusions>
 		</dependency>
+
+		<!-- Sentry error reporting (GlitchTip-compatible) -->
+		<dependency>
+			<groupId>io.sentry</groupId>
+			<artifactId>sentry-spring-boot-starter-jakarta</artifactId>
+			<version>8.5.0</version>
+		</dependency>
 	</dependencies>
 
 

backend/src/main/resources/application.yaml

@@ -118,3 +118,12 @@ ocr:
   sender-model:
     activation-threshold: 100
     retrain-delta: 50
+
+sentry:
+  dsn: ${SENTRY_DSN:}
+  environment: ${SPRING_PROFILES_ACTIVE:dev}
+  traces-sample-rate: ${SENTRY_TRACES_SAMPLE_RATE:1.0}
+  send-default-pii: false
+  enable-tracing: true
+  ignored-exceptions-for-type:
+    - org.raddatz.familienarchiv.exception.DomainException

backend/src/test/resources/application-test.yaml

@@ -23,8 +23,6 @@ otel:
 # Disable trace export in tests — prevents OTLP connection attempts when no Tempo is running.
 # Sampling probability 0.0 means no spans are created, so no export is attempted.
 management:
-  server:
-    port: 0   # random port per context — prevents TIME_WAIT conflicts when @DirtiesContext restarts the context
   tracing:
     sampling:
       probability: 0.0

docker-compose.yml

@@ -147,6 +147,8 @@ services:
       SPRING_MAIL_PROPERTIES_MAIL_SMTP_STARTTLS_ENABLE: ${MAIL_STARTTLS_ENABLE:-false}
       APP_OCR_BASE_URL: http://ocr-service:8000
       APP_OCR_TRAINING_TOKEN: "${OCR_TRAINING_TOKEN:-}"
+      SENTRY_DSN: ${SENTRY_DSN:-}
+      SENTRY_TRACES_SAMPLE_RATE: ${SENTRY_TRACES_SAMPLE_RATE:-1.0}
       # Observability: send traces to Tempo inside archiv-net (OTLP gRPC port 4317)
       # Tempo is defined in docker-compose.observability.yml (future issue).
       # OTLP failures are non-fatal — backend starts cleanly without the observability stack.