docs: correct Studio .11 profile validation evidence

[PurplePrintAI]

Summary

• Correct the .11 upgrade validation record: the pre-upgrade profile copy targeted an obsolete openscreen directory, not the active openscreen-subscription profile.
• Withdraw the unsupported claim that six active profile files were hash-identical across the .11 upgrade.
• Record the evidence that is actually available: the verified pre-.10 active-profile backup, current presence of all 19 checked files (18 matching hashes; one differs with unknown timing/cause), and a verified post-.11 active-profile snapshot of 5,628 files and 29 critical hashes.

The public .11 release notes already contain a prominent correction. This PR brings the repository changelog and validation document into agreement. It changes documentation only; the tagged application binary is unchanged.

Verification

• npm run docs:check passed (31 files).
• git diff --check passed.