Manual real-provider proof. Linux, Chromium browser panel, 1280x800 CSS pixels (screenshots 2560x1600), light theme. Each checkout ran `T3CODE_DEV_SEED=0 vp run dev` against its own fresh .t3 database. Claude Code 2.1.325, Haiku 5.5 through the configured Anthropic-compatible proxy. No replay and no tests used as evidence.

1. Create an empty git project and launch the ALPHA prompt with seed.py (the script consolidates the shell commands used).
2. Pair the web client using the startup pairing URL and navigate directly to /<environmentId>/<encodedThreadId>.
3. Close the thread details panel so the machine label is outside the capture.
4. In the header thread actions menu, choose Rename thread, replace Thread title with Zebra Renamed Title 4242, and press Enter.
5. Type Now reply with just the word BRAVO, no tools. into the composer and press Enter. Wait for BRAVO.
6. Read the provider thread nativeThreadRef from the isolated database and the corresponding Claude JSONL custom-title records with inspect-session.py. Its local .proof-config.json supplies database, thread and commit. Only those synthetic records are printed.
7. Stop the dev runner via its tracked terminal session, restart the same dev command, and run `node apps/server/src/bin.ts thread send <threadId> "Reply with just the word CHARLIE, no tools." --wait --json --base-dir .t3`. Inspect the same native session again.
8. Show the inspection output in the app terminal with `export PS1='$ '; clear; python3 proof.py`. Blur the terminal, take two screenshots at least 500ms apart, verify pixel identity, and inspect the capture.

Base: native title remained the seed after BRAVO and CHARLIE; same native session. Head: native title became Zebra Renamed Title 4242 after BRAVO and remained so after CHARLIE in the same session.

Additional head check: stop the server; run `claude --resume <nativeSessionId> --model claude-haiku-5-5 --ax-screen-reader`, accept trust for the synthetic project, enter `/rename Native Renamed 4242`, then `/exit`. Restart the server and send Reply with just the word DELTA, no tools. through the T3 CLI. The session title remains Native Renamed 4242 while the T3 title stays Zebra Renamed Title 4242.

The head rename flow was repeated on a second synthetic thread to replace a terminal capture where the inspection command had been typed before the terminal was ready. Both runs produced the same successful synchronization. Video shows the first head run, paired still shows the repeat. Proof helper files caused harmless changed-file summaries; the model did not use tools.