Linux desktop proof. Build each checkout with its own dependencies, desktop bundle and server bundle. Start its web development server on 127.0.0.1:19339 with T3CODE_DEV_SEED=0, T3CODE_PORT=19338 and PORT=19339. Launch desktop-driver.cjs under headless-desktop with PROOF_ROOT, APP_CHECKOUT, PROOF_SIDE and a fresh PROOF_HOME. Its real shell.openExternal wrapper records destinations and forwards them unchanged.

Use a synthetic dockware SSH account, key loaded into an SSH agent, sshd on 127.0.0.1:10171, and a synthetic git project /var/www/html containing README.md. Do not supply a port in SSH config. The account has Node available for T3's real remote backend. Zed needs writable short XDG_DATA_HOME and ZED_ALLOW_EMULATED_GPU=1 on this software-rendered VM. Register actual vscode:// and zed:// desktop handlers to isolated real editor installations. VS Code has the real Remote-SSH extension.

In the driver REPL choose app.windows().find(w=>w.url().startsWith('t3code-dev:')), close devtools, and set the T3 window to 1280x900 at 0,0. The Xvfb screen is 1920x1080. Run seed-ui.cjs to add the saved SSH environment and remote project through the UI. Use capture-actions.cjs for each editor. In VS Code accept the real folder-opening prompt. On base the connection fails; on head open README.md. Repeat with Zed. The final Zed head recording reopens the same remote project, so its saved README tab is restored.

Both sides use the same light themes and viewport. VS Code result stills are 1440x900; Zed result stills are 1536x1080. URI stills crop the native VS Code prompt. All selected stills were captured twice 500 ms apart and were byte-identical. Every published still and recording contact sheet was visually inspected. Recordings contain white boxes over environment/machine labels only. No model turns or tests supplied evidence.

The runtime transcript contains actual forwarded destinations, actual Remote-SSH output and the real desktop IPC return value for the explicit-port Zed URI. The base tries port 22; head authenticates on port 10171. The head opens the remote project in both editors.

AI-assisted; verified with the tests and tools listed above.