fix(mdns): send responses from UDP 5353 (GitHub Issue #1)

[sherief-nv]

PAIR release intent

Changelog title

fix(mdns): send responses from UDP 5353 (GitHub Issue #1)

Changelog body

• Discovery traffic now originates from UDP 5353, allowing standards-compliant mDNS peers and network reflectors to accept PAIR node records.

Bumps

• services: patch
• nvpair-proxy: none
• nvpair-cluster-manager: none
• nvpair-engine-manager: none
• nvpair-errors: none
• nvpair-job-scheduler: none
• nvpair-manual-nodes: none
• nvpair-node-info: none
• nvpair-node-scanner: patch
• nvpair-node-settings: none
• nvpair-tui: none
• nvpair-ui-broker: none
• nvpair-workload-manager: none

Summary

• Bind mDNS responses, announcements, goodbyes, and supplemental discovery queries to UDP source port 5353.
• Preserve per-interface sending and platform-specific socket sharing.
• Add source-port regression tests, architecture documentation, and native Linux, Windows, and macOS CI coverage.

Test plan

• Run tests in every services Go module, including cross-process tests.
• Run focused mDNS/discovery tests 20 times and run go vet.
• Run desktop typecheck, lint, dead-code, unit, and service-contract checks.
• Build all modular binaries and the standalone Windows services bundle.
• Cross-build changed packages for Windows, Linux, and macOS.
• Confirm reflected discovery and source port 5353 on the reported two-VLAN setup.

[Noah-Tervalon-Nvidia]

approved, gonna go ahead and fix the description so it passes the intent check.

[Noah-Tervalon-Nvidia]

Just noting https://github.com/woodsonl opened #70 with similar changes addressing the same issue. These changes supersede those, but I want to give them a shoutout for the work they did. Woodsonl we will make sure to mention you in the next set of release notes since your contributions are effectively included here.