fix(edge): reduce search engine override risk on Windows

[sonwr]

Summary

• add a Windows/Edge reproduction matrix for issue Microsoft Edge still overrides search engine #49
• apply Edge Windows policy flow in two phases to avoid policy clobbering order issues
• add a verification checklist and workaround notes for operators

Commits

• docs(edge): add issue Microsoft Edge still overrides search engine #49 Windows reproduction matrix
• fix(edge): apply Windows Edge policies in two phases
• docs(edge): add issue Microsoft Edge still overrides search engine #49 verification checks and workaround notes

Verification

• added scripts/verify-edge-policy-order.sh for local checks
• documentation updated in edge/README.md and edge/verification-checklist.md

Please review behavior on affected Windows + Edge versions from the #49 reproduction matrix.

[corbindavenport]

Was there ever confirmation that splitting the registry installation into two steps fixes this problem? I've still only seen one report of this happening (I'm back to using Edge on Windows, so maybe I'll get it as well), this is a lot of added complexity and technical-focused documentation for a fix that might not be required.