Complete Phase C — Quick transition renderers and closure

[Basjohn]

Phase C implementation closure.

Landed on this branch:

• Quick renderer ports for Diffuse, Ripple/Raindrops, Crumble, Particle, and Burn
• all 12 canonical production transitions represented in the lazy Quick implementation registry
• canonical Settings/default/random parameter resolution before render admission
• permanent canonical-registry <-> Quick-registry parity gate
• expanded Phase-C real-GL sign-off wrapper/case matrix
• transition authoring documentation rewritten for the landed Quick/QSGRenderNode contract
• durable Spec/Compositor/Contracts reconciled so QSGRenderNode is the selected inline custom-GL seam
• Current_Plan promoted to Phase D ACTIVE while Phase-C hardware/eyes-on acceptance remains explicit debt
• CI/Harness/TestSuite docs record the observed hosted-runner failure modes
• Windows CI checkout now fetches full Git history because permanent Bubble guards use historical git show

Independent source/diff audit completed before final branch update. No production/full compiled build was run.

Known deferred sign-off:

• focused Phase-C pytest execution on a capable clean checkout
• isolate current broad-suite shutdown/hang behavior
• real-GL transition smoke matrix
• physical two-display / normal-high-refresh / eyes-on effect parity where applicable

A deferred failure should reopen only the smallest demonstrated Phase-C defect; Phase D is otherwise admitted.