Adds `bun run profile:session`: creates a session, opens it in a real
browser, dispatches a prompt through the supported `openchamber session` CLI,
and records until the session reports itself idle. No input is synthesised, so
everything captured is the app reacting to its own event stream.
Streaming is judged by responsiveness rather than totals, so the report leads
with the long-task distribution, style recalculation and layout rates, frame
production, and the application's own stream counters.
Two failure modes are detected rather than reported as clean results. A session
belonging to a directory the browser is not viewing renders nothing and
produces a perfectly quiet profile, so the run verifies both new message
elements in the DOM and message-list render counters. And `RunTask` is only
emitted under the disabled-by-default timeline category, so a capture without
it reports zero long tasks; the missing-task case is now called out instead of
being shown as zero.
Metric helpers are shared with the idle profiler.
Idle cost depends on which surfaces are mounted, so the profiler needs to
reach those states without a human driving the UI.
`--panel <mode>` opens the context panel by seeding the persisted store the
app reads on boot, using the same tab identity rules as `useUIStore`.
`--then-tab <name>` navigates through the router after settling, which leaves
already-mounted surfaces mounted and measures what a screen keeps doing once
the user has moved on. Both drive real application state instead of
synthesising clicks, so the recorded window stays free of input-driven work.
Adds `bun run profile:idle`: a fully unattended capture of what OpenChamber
does while nobody interacts with it. It reports main-thread busy time, style
recalculation and layout rates, DOM node and listener growth, heap trajectory,
a CPU sampling profile, and per-call-site attribution of timer, animation
frame, and observer work.
Chrome throttles timers and stops producing frames for occluded or backgrounded
windows, which silently reports an idle-looking renderer regardless of what the
page schedules. Launch flags now disable that throttling, and every run measures
frame liveness so a throttled capture is reported as a warning rather than as a
clean result.
CDP launch and client code is shared with the existing browser profiler.
Bohdan Triapitsyn