Add a non-blocking runtime publish path and switch hot-path publishers to it.
Enforce subscription timeout boundaries, keep ordered subscriber snapshots up to date on subscribe changes, expose all runtime kinds to process hooks, add safe log attrs for non-agent events, and close the gateway message bus on full shutdown.
Migrate hook observation to runtime events and update the process hook notification protocol. Add runtime event publication for message bus failures, channel lifecycle/outbound flow, gateway reloads, MCP server state, and MCP tool calls.
Validation: go test ./pkg/events/... ./pkg/bus ./pkg/agent ./pkg/channels ./pkg/mcp ./pkg/tools/integration ./pkg/gateway; make lint
