fix: schedule quiet wraps at their slot deadlines

[TheCryptoDonkey]

QuietTransport could skip an entire slot when its random send offset fell after the last fixed timer poll. Short intervals were especially affected: polling once per interval kept the same phase and could postpone queued messages for many slots while also omitting fillers.

Schedule the selected deadline directly, recheck long waits for clock changes, and retry refused publishes after one second. Preserve the custom scheduler seam, non-overlapping writes, same-wrap retry and no catch-up bursts. No event format, key derivation or dependency changes.

Validation: three deterministic default-timer regressions fail before the fix and pass afterwards, covering eight-second and five-minute slots plus same-wrap retry. All 82 tests pass locally on Node 22/24; hosted CI is green on both versions. Type checking, package build and a cold-install API smoke pass. An independent consumer checkout tested the packed candidate in Chromium, Firefox and WebKit on Linux CI; all passed.