Keep Liquid Glass HUD alive at screen edges

[yvette-carlisle]

Summary

• Add shared inclusive edge geometry for capture overlay/window/screen routing.
• Clamp edge-local pointer positions so the Liquid Glass HUD stays visible at screen max edges.
• Add native host kit probe coverage for min/max edge placement and outside-edge rejection.

Validation

• cargo make checks
• git diff --check

Notes

• A manual local HUD-edge smoke was attempted before commit, but the harness did not enter capture on this machine; it was not counted as a passing signal.