fix(backend): switch to sentry-spring-boot-4:8.41.0 for Spring Boot 4/SF7 compatibility

sentry-spring-boot-starter-jakarta 8.5.0 does not support Spring Boot 4.0 —
it logs an "Incompatible Spring Boot Version" warning and its SentryAutoConfiguration
crashes SF7 bean-name generation. sentry-spring-boot-4 (added in 8.21.0) is the
dedicated Spring Boot 4 module with a fixed auto-configuration class.

- Replace sentry-spring-boot-starter-jakarta:8.5.0 with sentry-spring-boot-4:8.41.0
- Delete SentryConfig.java — workaround no longer needed, auto-config handles init
- Remove spring.autoconfigure.exclude from application.yaml + application-test.yaml
- Delete SentryConfigTest.java — tested the deleted workaround class
- Update ApplicationContextTest: assert Sentry.isEnabled() is false when no DSN set

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

backend/src/main/java/org/raddatz/familienarchiv/config/SentryConfig.java

@@ -1,39 +0,0 @@
-package org.raddatz.familienarchiv.config;
-
-import io.sentry.Sentry;
-import jakarta.annotation.PostConstruct;
-import org.raddatz.familienarchiv.exception.DomainException;
-import org.springframework.beans.factory.annotation.Value;
-import org.springframework.context.annotation.Configuration;
-
-// SentryAutoConfiguration is excluded (see application.yaml) because Spring Boot 4 / Spring
-// Framework 7 cannot generate a bean name for the triply-nested
-// SentryAutoConfiguration$HubConfiguration$SentrySpanRestClientConfiguration class.
-// This bean replicates the essential init: DSN, environment, sample rate, PII guard,
-// and DomainException filter.
-@Configuration
-public class SentryConfig {
-
-    @Value("${sentry.dsn:}")
-    private String dsn;
-
-    @Value("${sentry.environment:dev}")
-    private String environment;
-
-    @Value("${sentry.traces-sample-rate:1.0}")
-    private double tracesSampleRate;
-
-    @PostConstruct
-    public void init() {
-        if (dsn == null || dsn.isBlank()) {
-            return;
-        }
-        Sentry.init(options -> {
-            options.setDsn(dsn);
-            options.setEnvironment(environment);
-            options.setTracesSampleRate(tracesSampleRate);
-            options.setSendDefaultPii(false);
-            options.addIgnoredExceptionForType(DomainException.class);
-        });
-    }
-}

backend/src/main/resources/application.yaml

@@ -38,13 +38,6 @@ spring:
           starttls:
             enable: true
 
-  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 initialized manually via SentryConfig instead. See #580.
-      - io.sentry.spring.boot.jakarta.SentryAutoConfiguration
-
 server:
   # Behind Caddy/reverse proxy: trust X-Forwarded-{Proto,For,Host} so that
   # request.getScheme(), redirect URLs, and Spring Session "Secure" cookies