Unit tests for tracks$ and trackBySource$, an end-to-end check of isActive$ through a mute cycle (skipped on Chromium, whose fake microphone the SFU never hears), the architecture document brought in line with the track list, and the changed behaviour recorded in the plan.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Update the public API to export the primitives and operators the call
model needs, and change `LocalMediaInputs` from observable flags to
immediate booleans with imperative setters. Add session timings, media
quality and capture settings as configuration options, and allow the
host to override the transport discovery with explicit URLs.
