Aurora EDF scheduler attribution

AuroraEdfScheduler.java is derived from the EDFSchedulerThreadPool implementation
in Tuinity/LeafPile v1.2.0, commit:
8c9fa2c5b8ac063075977efc048f6ec0299f24da
Original authors: Spottedleaf and Tuinity/LeafPile contributors.
Source: https://github.com/Tuinity/LeafPile
License: GNU GPL version 3; included as LICENSE_LEAFPILE.

SourbyCraft changes: cancellation lifecycle, awaiting-task replacement links,
deadline rearming, shutdown admission, immutable scheduler owner publication,
and integration as an Aurora-owned EDF backend. The original waiting policy and
underlying LeafPile utilities remain in use. This is a derived implementation,
not an independently designed scheduler.

Related upstream review: yunuservices, "Fix EDF scheduler cancellation and state
visibility", Tuinity/LeafPile pull request #6, open when reviewed 2026-10-06:
https://github.com/Tuinity/LeafPile/pull/6
Reviewed head: 5348d20288bdad210750c5e5a66a67e1e0021cd2
The local fix retains SourbyCraft's public SchedulableTick fields for compatibility
and additionally repairs awaiting replacement links and deadline rearming.
