Realign periodic polling to the deadline after a visibility catch-up

An overdue refresh on return to a visible tab advanced the due time but kept
the old setInterval phase, so the next phase tick was skipped and the gap
could approach two intervals (also after a failed resume refresh). The
catch-up now re-arms the interval at the new deadline. Interval ticks no
longer compare against the due time, since the phase and the deadline share
one origin. Overlap prevention and teardown are unchanged, and a stale
listener cannot re-arm a stopped loop.

Tests cover the next poll one interval after a between-ticks resume, with a
successful and a failed catch-up refresh.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

changelog.d/1282-polling-issue-fix.md

@@ -1,4 +1,4 @@
-- Pause periodic network updates in hidden tabs (asturksever, #1282).
+- Pause periodic network updates in hidden tabs; the overdue update on return restarts the polling schedule, so the next poll follows one interval later even when that update fails (asturksever, #1282).
 - Report and guard browser visibility during Transit QA so hidden-page polling pauses cannot masquerade as playback regressions (asturksever, #1282).
 - Require each live city to supply its own feed vehicles in Transit QA; retained vehicles cannot qualify another city (asturksever, #1282).
 - Bound the Transit card-anchor probe by observed poll coverage instead of a fixed 20-second window (asturksever, #1282).