Drift audit: pin/spec/version drift detected

[displayxr-publish-bot]

Automated cross-repo drift audit (scripts/drift_audit.py, epic #691 / #695).

• stale-pin: pins displayxr-common @ v2.7.0 but latest tag is v2.8.1
• common-pin-spread: displayxr-common pins disagree across consumers: displayxr-cef-host=v2.7.0, displayxr-demo-avatar=v2.8.1, displayxr-demo-earthview=v2.7.0, displayxr-demo-gaussiansplat=v2.8.1, displayxr-demo-modelviewer=v2.8.1

Re-run scripts/drift_audit.py after fixing to clear this issue.