Adds a MkDocs on_config hook (scripts/mkdocs_hooks.py) that appends the
release version as the ?v= cache-buster on v2_elite.css and v2_filter.js,
resolved from $SITE_VERSION or the latest git tag. Removes the hand-
maintained query strings from v2-mkdocs.yml.
This prevents the class of bug fixed in v2.9.46: a CSS/JS change going
invisible to returning visitors because ?v= was never bumped (it had
drifted to 2.9.42 for the CSS and 2.9.19 for the JS). Now every release
stamps a fresh URL automatically.
Falls back to leaving URLs untouched when no version is resolvable (e.g.
local mkdocs serve in a shallow checkout), so the build never fails.
Verified: build from git tag -> ?v=2.9.46; SITE_VERSION=9.9.9 -> ?v=9.9.9.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
