bbctrl.Trace records monotonic-anchored events from process start.
Ctrl, Comm, the Web layer and __init__ are instrumented so a single
GET /api/diag/timing returns a full timeline of import, controller
init, AVR connection, first websocket, and first GET /. The
restart-timing.js client posts performance.now() marks back so the
browser side can be aligned in the same view.
Used to drive the cold-boot optimisations that reduce listen latency
on the Pi by ~8s.
