SHiRE Academy Round 3 contract and timeout repair

Completed:
- Installed the previously syntax-validated Round 3 source repair.
- Safely migrates root acceptance_criteria into transfer_project.
- Prunes only identical duplicate criteria.
- Rejects conflicting criteria.
- Preserves strict Round 3 schema validation.
- Structured-output contract failures are content failures.
- Genuine structured timeout and transport failures remain infrastructure.
- Updated the timeout self-test to test classifier behaviour rather than
  requiring the literal source token "http 504".
- Verified HTTP 504 timeout payloads remain retryable infrastructure.
- Verified HTTP 422 contract failures are not infrastructure.
- Preserved Practice Service root:root 0644 ownership.
- Preserved all successful learning history.
- Preserved every Forge lock.
- Practice and autopilot state remained byte-for-byte unchanged.
- No Academy service or timer was restarted or modified.
- Sentinel was not modified, stopped or restarted.

Evidence:
/SHiREVault/Backup/OSBackups/SHIRE-ACADEMY-ROUND3-TIMEOUT-CONTRACT-REPAIR-20260805T123006Z