docs: keep root README.md version pins in sync with core/VERSION

Follow-up from #798 by @ziyaad-mallick — thanks again for that PR!

What

Nothing keeps the root README.md's version numbers in sync with core/VERSION. scripts/release/sync-versions.sh and scripts/validation/gates/check_release_version_coherence.sh only touch bindings/** files — never the root README. Today the "all SDKs ship on one version line" sentence (README.md:434) and the per-package install pins (README.md:198-201, 235-239, 271, 306, 375) already disagree with each other and with what's actually published: npm view @runanywhere/[email protected] and @runanywhere/[email protected] both 404, and https://pypi.org/pypi/runanywhere/json 404s too, so the documented pip install runanywhere==0.20.11 and npm install @runanywhere/[email protected] ... commands fail for anyone who copies them today.

Why it matters

A reader who follows the README's own install commands hits a 404 on the first try, which is a bad first impression and generates avoidable support questions.

Suggested approach

Add the root README.md version line and install-command pins to sync-versions.sh so a release bump updates them automatically, and add a check to check_release_version_coherence.sh so a stale README fails the gate the same way a stale binding does.

Done when

• sync-versions.sh updates README.md's version line and install-command pins on a version bump
• check_release_version_coherence.sh fails when README.md's version references drift from core/VERSION

Not blocking #798. @ziyaad-mallick, you know this code well now — you're welcome to take this one if you're interested.

Opened with help from Claude Code and Codex.

Reviewed with help from Claude Code and Codex.