* Skip session warnings that fire after their window
The warning timers run on the monotonic clock, which does not advance
while an Android device is suspended. A timer armed for T-10 or T-2 can
therefore fire long after the window it was armed for, delivering a
"session expires soon" notification once that window is already gone.
Gate both callbacks on the wall clock at fire time: the T-10 warning is
skipped once the final-warning window has been reached, and the final
warning is skipped once the deadline itself has passed. Both set their
edge guard before returning so a skipped warning cannot fire again for
the same deadline.
* Harden the late-warning guards
Clamp a non-positive final lead to zero in the T-10 guard so a disabled
final warning cannot move the cutoff past the deadline, matching how
armTimerLocked already treats it.
Strip the monotonic reading from both sides of the comparison so the
guard measures wall-clock time regardless of how the caller built the
deadline. The production deadline comes from a protobuf timestamp and
has no monotonic reading; this keeps the guard correct for callers that
derive one from time.Now.
* Log the deadline and lateness on skipped warnings
Include the deadline and how far past the cutoff the timer fired, so a
debug bundle shows how long the device was suspended.
* Inject the clock into the late-warning guard and cover it with tests
The guard read time.Now internally, so the skip paths were reachable
only through a deadline already in the past and the boundary depended
on real time. Extract the comparison into isLate and read the time
through a nowFn field, so tests can place a resume anywhere around the
deadline without sleeping.
* Send the final warning when the T-10 timer fires inside its window
A suspend between roughly eight and ten minutes long made the T-10
timer fire inside the final-warning window and the final timer fire
after the deadline, so both were skipped and a user who resumed with
time left got no warning at all. When the T-10 timer fires late but
before the deadline, send the final warning in its place and mark it
fired so the delayed final timer does not repeat it.
* Respect dismissal when promoting a late warning to the final one
fireFinal skips the final warning once the user dismissed the deadline,
but the promoted path did not, so a dismissed deadline could still get
a final warning. Check the dismissal first, and give each skip reason
its own log line so an already-fired final warning no longer logs a
negative lateness.
* Add a deadline-only mode to the session watcher
Android will schedule its own expiry warnings from the deadline, so
the engine must not arm the T-10 and T-2 timers there. NewDeadlineOnly
keeps the deadline validation, the recorder propagation and the
logging, and skips only the timers, so the status snapshot the app
reads stays correct and an out-of-range deadline is still rejected.
* Use the deadline-only watcher on Android and drop the warning callbacks
The warning timers run on the monotonic clock, which does not advance
while the device sleeps, so a warning armed for T-10 could fire long
after its window. The app now schedules the warnings itself with
WorkManager, anchored to the wall clock, from the deadline it reads
through SessionExpiresAtUnix on every OnStateChanged.
Wire the deadline-only watcher into the android build and remove the
event-driven path from the gomobile surface: OnSessionExpiring, the
event subscription behind it and DismissSessionWarning, which the app
never called.
* Describe the late-warning guard without naming Android
The guard stays for the desktop builds, where a timer can also stall
across a sleep. Android no longer arms the timers at all.
