fix(backend): exclude SentryAutoConfiguration — Spring Boot 4/SF7 bean name incompatibility

SentryAutoConfiguration$HubConfiguration$SentrySpanRestClientConfiguration is a triply-
nested @Configuration class conditionally loaded when RestClient is on the classpath
(always true on Spring Framework 7). Spring Framework 7's bean name generator fails
on such deeply-nested @Import-ed classes, crashing every @SpringBootTest context.

Replace the broken auto-configuration with a minimal SentryConfig bean that calls
Sentry.init() with the same properties (DSN, environment, sample rate, PII guard,
DomainException filter). Unexpected 5xx exceptions are forwarded to Sentry via
Sentry.captureException() in GlobalExceptionHandler.handleGeneric().

Also add management.server.port=0 to application-test.yaml to eliminate TIME_WAIT
conflicts from @DirtiesContext restarts on the fixed management port 8081 (see #593).

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

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

@@ -13,6 +13,12 @@ spring:
     password: test
   mail:
     host: localhost
+  autoconfigure:
+    exclude:
+      # SentryAutoConfiguration fails on Spring Boot 4/Spring Framework 7: Spring cannot generate a
+      # bean name for the triply-nested SentryAutoConfiguration$HubConfiguration$SentrySpanRestClientConfiguration.
+      # Sentry is wired manually via SentryConfig instead. See #580.
+      - io.sentry.spring.boot.jakarta.SentryAutoConfiguration
 
 # Disable OTel SDK entirely in tests — prevents auto-configuration from loading resource providers
 # (e.g. AzureAppServiceResourceProvider) that fail against the semconv version used here.