The two-way live run unified the propped-phone mirror onto the real
ExerciseProgressView driver, whose phase views anchor their timers to a
local Date() captured when the page becomes active. For a remote-driven
transition that meant anchoring at phaseStart + delivery-latency +
render-time, so the receiver's countdown lagged the driver — visibly so
iPhone->watch, where the watch is the slower receiver (apply -> SwiftUI
re-render -> TabView animation -> phase view activates).
The frame already carries phaseStart/phaseEnd wall-clock anchors (the way
the old read-only mirror counted off them). Honor them: when a phase is
reached by applying a remote frame, the active phase view anchors its
timer to the frame's phaseStart/phaseEnd instead of local now. Scoped to
the remote-driven page (remoteAnchorPage) so a local swipe or auto-advance
still self-anchors; any local transition clears it. Applied symmetrically
to both the iPhone and watch drivers.
Delivery latency no longer shifts the displayed timer in either direction
(limited only by sub-second inter-device clock skew), and the auto-advance
at zero fires together since both share the same phaseEnd.
Claude-Session: https://claude.ai/code/session_01SCv7zvGFcKy47KSTnTLxRe
rzen
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