Refresh WebGL delivery archives from current builds

The deployable zip files had drifted from the live/playback/trial WebGL
folders after the latest interface fixes. Rebuild the three archives directly
from the current Unity-WebGL entry directories so the website handoff packages
match the verified local outputs byte-for-byte.

Constraint: Website handoff is the three Unity-*-WebGL.zip archives, not only the expanded preview directories.
Rejected: Rely on zip timestamps | file times did not prove that Build assets matched the current directories.
Rejected: Hand off expanded folders only | the requested deliverables are the three zip archives.
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Before future website handoffs, extract each archive and compare file lists plus hashes against live/playback/trial.
Tested: Extracted all three refreshed zips and verified 17 files each with no missing, extra, or SHA256-different files against current Unity-WebGL directories.
Not-tested: Remote website deployment behavior; this commit only refreshes static archive contents.

Author: zyfkid