Document Tribes status monitoring

[sainadh777]

Summary

• Replace the placeholder Tribes status page with a guide to channel, membership, transport, interceptor, and session replication status exposed through JMX.
• Remove the completed TODO 75.2 entry and add a documentation changelog entry.

Rationale and impact

The checked-in TODO identifies the empty status page. Operators can now find the available MBeans and interpret key membership and queue signals without reading the implementation. This is documentation only; runtime behavior and public APIs are unchanged.

Validation

• Linux (Eclipse Temurin 21.0.12, Ant 1.10.15, native Docker volume): ant -Dbase.path=/workspace-cache -Dexecute.validate=true validate — passed; Checkstyle 14.1.0 checked 7,687 files.
• ant -Dbase.path=/workspace-cache build-docs — passed; generated docs/tribes/status.html and verified all linked local pages exist.
• ant -Dbase.path=/workspace-cache clean deploy — passed; clean source build and generated distribution.
• ant -Dbase.path=/workspace-cache test — passed, unfiltered: 654 suites, 41,311 tests, 0 failures, 0 errors, 330 skips (25m52s).
• Generated distribution smoke: started Tomcat, received HTTP 200 for /docs/tribes/status.html, and stopped cleanly — passed.
• git diff --check — passed. SHA-256 of all three changed files matched between the worktree and Linux test copy.

[sainadh777]

@markt-asf, could you review this Tribes status documentation when convenient? Your prior work on the Tribes docs would help check the JMX guidance. Thanks.

[sainadh777]

@rmaucher, could you review the JMX guidance in this Tribes status page when convenient? Your recent update to JmxRegistry.java is directly relevant. Thanks.