fix(gateway): guard Teams multiplex listener ownership

[JoelMTaylor]

Summary

• classify Microsoft Teams as a host-port-binding gateway platform
• expose the Teams default listener port in gateway topology reporting
• reject Teams on secondary multiplex profiles with the existing degradable configuration error

Why

The Teams adapter always starts an HTTP listener on its configured port (3978 by default), but Teams was missing from the shared port-binding registry. In multiplex mode, secondary profiles could therefore attempt to start additional Teams listeners on the same host port, producing address-in-use failures and unreliable inbound delivery.

The default profile should own the shared listener and route profile-specific traffic through the existing multiplex URL prefixes.

Impact

Misconfigured secondary Teams profiles are skipped with an actionable warning instead of attempting a conflicting socket bind. Single-profile Teams gateways are unchanged.

Validation

scripts/run_tests.sh tests/gateway/test_multiplex_adapter_registry.py --file-timeout 60 -- -q

Result: 16 passed.

[teknium1]

Thanks @JoelMTaylor — Merged via #101252 (2e25b47) on current main.

Your commits from this PR were cherry-picked onto the salvage branch with your git authorship preserved, so the credit is yours in git log.

Closing this PR since the work is now on main.