Add @ConditionalOnMissingBean guard to StepEventPublisherBridge bean

[casc84ab]

Summary

• Added @ConditionalOnMissingBean(type = "org.fireflyframework.transactional.saga.events.StepEventPublisher") to StepBridgeConfiguration.stepEventPublisherBridge() to prevent duplicate bean registration.
• The condition checks for the StepEventPublisher interface type to detect beans from any bridge implementation (core, domain, or data).

Test plan

• Verify application starts correctly with only fireflyframework-domain on classpath
• Verify application starts correctly with both fireflyframework-domain and fireflyframework-core on classpath
• Confirm only one StepEventPublisher bean is registered when multiple modules are present

[ancongui]

Code Review: Add @ConditionalOnMissingBean guard to StepEventPublisherBridge bean

Summary

This PR adds @ConditionalOnMissingBean(type = "org.fireflyframework.transactional.saga.events.StepEventPublisher") to the stepEventPublisherBridge() bean method in StepBridgeConfiguration. This prevents duplicate StepEventPublisher bean registration when multiple bridge modules are on the classpath.

CI Status

✅ All checks pass (CodeQL, build)

Findings

1. Correct use of string-based type reference (Severity: None — good practice)
Using type = "org.fireflyframework.transactional.saga.events.StepEventPublisher" is the correct approach here since it avoids potential ClassNotFoundException if the transactional module isn't on the classpath. This is consistent with Spring Boot auto-configuration conventions.

2. Condition checks for interface type, not concrete class (Severity: None — well designed)
The condition checks for the StepEventPublisher interface rather than a specific implementation. This means ANY implementation of the interface (from core, domain, or data modules) will prevent this bean from being registered — which is the correct behavior.

3. @Primary + @ConditionalOnMissingBean combination (Severity: Low — same as core PR)
Same note as the core PR: consider whether @Primary is still needed since @ConditionalOnMissingBean prevents multiple beans. Not a blocker.

4. Auto-configuration ordering determinism (Severity: Medium — worth noting)
Same concern as the core PR: with all three bridge modules using @ConditionalOnMissingBean, the "winner" depends on Spring's auto-configuration order. Consider using @AutoConfigureBefore/@AutoConfigureAfter to make this deterministic.

Recommendation

APPROVE — Clean, minimal change that follows Spring Boot conventions. The change is safe and correctly prevents bean conflicts.