Mend the test prerequisites, document local CCTV packs without the dead demo feed, and credit the author

CONTRIBUTING.md

@@ -34,16 +34,18 @@ Open `http://localhost:4173`. Before sending a PR run `npm run build`, `npm test
 - **`npm run test:track`** — the 3D flight-tracking regression harness. It
   drives the **real app** in headless Chromium, so it **requires a running
   dev server** (default `http://localhost:4173`). To target another instance,
-  run `npm run test:track -- --url <app-url>` (or `node scripts/track-regression.mjs --url <app-url>`).
-  depend on live OpenSky / adsb.lol / AISStream (those are optional or
-  rate-limited locally); it installs a persistent `fetch` shim that returns
-  synthetic aircraft in the exact upstream payload shapes the layers parse.
+  run `npm run test:track -- --url <app-url>` (or
+  `node scripts/track-regression.mjs --url <app-url>`). It does not depend on
+  live OpenSky / adsb.lol / AISStream (those are optional or rate-limited
+  locally); it installs a persistent `fetch` shim that returns synthetic
+  aircraft in the exact upstream payload shapes the layers parse.
 - **`npm run build`** — production Vite build. No server or credentials
   required; it validates that the client bundle compiles cleanly.
 
-If you change runtime behavior, update `docs/CURRENT-STATE.md` and
-`CHANGELOG.md` in the same PR. For a deeper catalog of what each harness
-checks and what it needs to run, see [TESTING.md](TESTING.md).
+Each feature also has its own headless gate; see
+[Feature regression gates](#feature-regression-gates) below. Docs and changelog
+rules are under [Pull requests](#pull-requests).
+
 ## Checking a built app locally
 
 Run `npm run build` followed by `npm run preview`. Preview serves the built