Release 20.9.0 (#1748)

* Release 20.9.0

Dates the changelog section. 24 commits since 20.8.0.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NGvtaUNATVCVxD2qcbiY4t

* Release: date 20.9.0 as the day it actually ships

The release was prepared on the 17th and is going out on the 18th. The date
in the changelog is the one readers use to place a version against their own
history, so it tracks the release, not the preparation.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NGvtaUNATVCVxD2qcbiY4t

---------

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: obiot

packages/melonjs/CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changelog
 
-## [20.9.0] (melonJS 2) - _unreleased_
+## [20.9.0] (melonJS 2) - _2026-10-18_
 
 ### Added
 - **`scaleRounding`**: `"integer"` constrains the automatic scale factor to a whole number of device pixels per source pixel, letterboxing whatever is left over, where the default `"fractional"` fills the container exactly. A 480 wide design in a 1280 wide container is scaled by 2.667, so some source pixels cover three device pixels and some cover two, which pixel art shows as uneven stems and shimmering edges and which browsers resolve differently, so the same scene looks crisp in one and soft in another. The rounding is applied in DEVICE pixels, since `devicePixelRatio` would otherwise put the fraction back. It affects `scaleMethod: "fit"` only, because every other method resizes the renderer to its container and so has no fixed factor to round