test(brain): add unit tests for recall, remember, messaging
Coverage: 5.3% → 92.8%. Tests cover DirectSubsystem (apiCall, remember,
recall, forget via httptest), messaging (sendMessage, inbox, conversation,
parseMessages, toInt), BrainProvider (gin handlers, routes, describe,
status), Subsystem bridge-backed handlers, and RegisterTools.
Also fixes build error in dispatch.go (removed KillGroup, Timeout,
GracePeriod fields no longer in process.RunOptions).
Co-Authored-By: Virgil <virgil@lethean.io>
0a77b058b6