Hermes-agent platform adapter that delivers Molecule A2A peer-agent
messages to a running hermes daemon over HTTP, and POSTs agent replies
back to the molecule-runtime callback URL.
Closes the MCP-style push parity gap for hermes workspaces:
- Single long-lived adapter session (no subprocess per message)
- MessageEvent(internal=True) bypasses per-platform user allowlist
for trusted A2A peer messages
- Optional shared-secret HMAC enforcement
- Per-chat callback URL learned from inbound payload
Requires hermes-agent ≥ the upstream PR
NousResearch/hermes-agent#18775 (PluginContext.register_platform_adapter
+ GatewayConfig plugin_platforms wiring + PluginPlatformIdentifier
helper + resolve_platform_id deserialization).
