[Bare7a]

📝 What changed?

The landing page and the README now open with a two-minute demo video, recorded by a new cargo xtask demo-video that tours the app in a hidden window against the e2e stack. The screenshots move to docs/ as their only copy, and the JSON viewer no longer shows stale values after Apply.

• Demo video: screenshots/video.rs plays the tour in the landing page's order, with a drawn pointer, fading captions and a visible click for every step. Loads happen between frames and off-camera changes crossfade, so nothing flashes or jumps. ffmpeg encodes the changed frames into docs/demo.mp4: 2:14 at 1080p30, under X's 2:20 limit.
• Landing page: the hero screenshot swaps in the video on click, so none of it loads before.
• README: a poster at the top, docs/demo.webp, opens the video on the site, since GitHub plays only its own uploads in a README. The gallery shows 800 px copies linked to the full-size screenshots.
• Screenshots: retaken at 1920 × 1080, which unattended runs now render in a hidden window on any display, and kept once as lossless WebPs in docs/screenshots instead of also as PNGs in .github/screenshots. docs-images makes the smaller copies, the link preview and the poster from them.
• JSON viewer: after Apply it shows the saved values, in table tabs and editable results, and it empties when Apply deletes the last row.
• Snapshot tooling: click targets use GPUI Kit's test lookups instead of home-made probes, and the registrations do nothing in release builds. Snapshot runs optimize the GPU readback and PNG crates through --config, leaving Cargo.toml alone.

🧩 Type of change

• 🐛 Bug fix
• ✨ Feature
• ♻️ Refactor
• ⬆️ Dependencies
• 📝 Docs or landing page
• 🛠️ Build, CI or packaging

🧪 Tested

• By hand on Windows
• By hand on macOS
• By hand on Linux
• Tests workflow on macOS and Windows

📖 Docs

• Updated the guide
• Updated the README or landing page
• No docs needed

📌 Notes