Stamp desktop-owned transcripts with the claude-desktop entrypoint while preserving the SDK runtime entrypoint used for provider authentication.
Tests: focused regression 41/41; chat contract 240/240; server 1622/1622; coverage 5/5 with changed lines 4/4.
Live-path proof: hermetic loopback transcript was visible in Claude Code 2.1.206 /resume; no real user credentials or config were used.
Constraint: check:impact remains policy-blocked until a PR has the allow-cli-core-change label.
Confidence: high
Scope-risk: narrow
