fix: include plugin platforms in status

[Rivuza]

Summary

• Trigger plugin discovery before hermes status reads plugin-registered platform entries
• Preserve existing built-in platform status output
• Add regression coverage for a plugin-registered messaging platform appearing in the status output

Test Plan

• /home/rivuza/hermes-agent/.venv/bin/python -m pytest tests/hermes_cli/test_status.py::test_show_status_includes_plugin_registered_platform -q
• /home/rivuza/hermes-agent/.venv/bin/python -m pytest tests/hermes_cli/test_status.py -q

Closes #44119

[liuhao1024]

✅ Verification: Clean Review

Reviewed this PR's diff. The fix correctly addresses the missing plugin platforms in hermes status:

1. Root cause identified — plugin adapters register during discover_plugins(), but show_status was reading platform_registry without triggering discovery first
2. Minimal fix — adds discover_plugins() call before iterating platform_registry.plugin_entries()
3. Test coverage — registers a fake platform via discover_plugins, verifies it appears in status output, and properly cleans up with unregister in a finally block

discover_plugins() is idempotent and already called during normal gateway startup, so calling it in show_status is safe.

No issues found.

[alt-glitch]

Duplicate of #44124 — same fix for #44119 (call discover_plugins() before status.py reads plugin-registered platform entries). #44124 is the earlier open PR.

[teknium1]

Thanks for the focused regression fix. The premise remains present on current main: hermes_cli/main.py:4256-4260 dispatches directly to show_status(), and hermes_cli/status.py:473-480 iterates platform_registry.plugin_entries() without first discovering plugins.

The proposed call matches the established enumeration pattern in hermes_cli/gateway.py:5096-5106. hermes_cli/plugins.py:2038-2044 explicitly defines default discovery as idempotent, and the added test targets the missing status-path registration behavior.

No blocking correctness or design-fit issues found. The member discussion identifies #44124 as the earlier duplicate, but current main still needs this behavioral guarantee.

Automated hermes-sweeper review.