Own a dedicated CDP-controlled browser window for Notion manual demo recording

Problem

The manual demo recorder still depends on matching whatever visible Google Chrome window happens to have the expected title fragment. Even with stricter matching and fail-fast behavior, this remains brittle because the recorder does not own the browser window lifecycle.

Why this matters

• Demo recording should not depend on the user keeping the right personal Chrome window visible.
• Window-title matching is safer now, but still operationally fragile.
• A dedicated browser window would let the recorder use CDP for navigation/state and ScreenCaptureKit only for final pixels.

Proposed direction

• Launch or attach to a dedicated demo Chrome instance/profile.
• Control the page exclusively over CDP.
• Persist a deterministic window identifier for ScreenCaptureKit capture.
• Keep tmux as the terminal-side control surface, but remove dependence on the user's ambient browser windows.

Acceptance criteria

• Recorder can create/reuse its own browser window without touching personal Chrome tabs.
• Window targeting no longer falls back to title-fragment guessing for the browser side.
• Full demo can be rerun end to end without manual browser-window setup beyond granting capture permissions.

Start at the manual demo recorder's browser-window targeting entry point and trace its CDP, ScreenCaptureKit, and tmux control flow. Define the dedicated Chrome instance or profile lifecycle and deterministic window identifier, then verify the end-to-end demo reruns without personal tabs or manual browser-window setup beyond capture permissions.