The raft platform plugin's check_raft_requirements() logged a WARNING every
time it returned False. Since check_fn is called on every load_gateway_config()
(~every 10s during normal gateway operation), users who don't have the raft
CLI installed get their logs flooded with no way to suppress it — hermes plugins
disable doesn't work for bundled platform plugins, and platforms.raft.enabled:
false doesn't gate the check_fn call.
Fix: make check_raft_requirements() a silent predicate (return True/False
only, no logging), matching the convention documented and used by other
platform adapters (e.g. teams/adapter.py). The caller in
gateway/platform_registry.py create_adapter() already emits its own warning
when requirements aren't met and an adapter is actually requested — that's the
correct place for a user-facing warning (fires once per connect attempt, not
once per config load).
Fixes#49234
Satisfies the repo-wide subprocess-stdin guard
(tests/tools/test_subprocess_stdin_guard.py); the long-lived bridge
child should not inherit the gateway's stdin.
Adds a Raft platform adapter as a bundled plugin (plugins/platforms/raft/)
connecting Hermes to Raft as an external agent via a wake-channel bridge.
The adapter starts a loopback HTTP endpoint, spawns 'raft agent bridge' as a
child process, and injects content-free wake hints into the gateway session
pipeline. The agent reads/sends messages through the Raft CLI; the adapter
never touches message bodies or delivery cursors. Activity observer hooks
report tool/LLM/session lifecycle events via a bounded at-most-once queue.
Auto-enables when RAFT_PROFILE is set.
Cherry-picked from PR #47629. Authored by skyzh (@xxchan).
