Fix silent connection errors in ConnectionContext with Micrometer alerting

[freddyDOTCMS]

Description

In ConnectionContext.close(), replace catch (Exception ignored) with a structured ERROR log entry and a Micrometer counter named analytics.connection.leak. This allows ops to alert on spikes in connection leaks rather than silently swallowing errors.

Improvement plan: https://docs.google.com/document/d/1hVfIurPqAJJ1PN1EalmvrWXnGNt5sY21MI-409lrXpU/edit?tab=t.klqavlz4cis7#heading=h.8vek9yxwq8yt

Parent epic: #35048

Acceptance Criteria

• catch (Exception ignored) removed from ConnectionContext.close()
• Replaced with a structured ERROR log entry (consistent with logging standard from Set up async structured JSON logging in analytics microservice #35056)
• Micrometer counter analytics.connection.leak incremented on each caught exception
• Counter is exposed via /actuator/metrics/analytics.connection.leak
• Log entry includes enough context to identify the source (customerId, connection details if available)

Additional Context

• Source task: Task 18 (Fix silent connection errors) from the improvement plan
• Parallelizable after Phase 1 — blocked by: Refactor analytics service ingest code #35050
• Related branch: issue-34849-Add-dotCMS-Analytics-Proxy-Endpoint-for-/v1/analytics/-to-dot-ca-event-manager

[freddyDOTCMS]

We already add a error log here

https://github.com/dotCMS/dot-ca-event-manager/commit/5604f55c7b80b20e63d92b68e8992ceaf49db849#diff-e2989df269b8333088354e6335ac2c41a87a94ae1bd3428a0cffd00dcf24a4a8R53

about the "Micrometer counter", We haven't include micrometer yet, and we are working right in a Monitoring plan to include observability to the event manager