fix:docs

DATA_SOURCES.md

@@ -125,6 +125,36 @@ the retrieval date (2026-07-30), exact download URL, license evidence, and the
 deterministic transform (`scripts/build-sf-neighborhoods.mjs`: `nhood` → `name`, ~2 m
 Douglas-Peucker simplification, 6-decimal rounding).
 
+### Pilot CCTV source packs (`config/`)
+
+`config/cctv_sources.shinjuku.json` is a **demo source pack** (3 cameras:
+Shinjuku Crossing, Shinjuku Station West, Shibuya Scramble) used for
+projection-pipeline testing. The feeds are Google-hosted sample MP4 videos
+(`storage.googleapis.com/gtv-videos-bucket/sample/`), not live public cameras.
+Camera poses (coordinates, heading, pitch, FOV, mount height) are fabricated
+priors placed at recognizable Tokyo intersections.
+
+Use the pack by setting:
+
+```bash
+CCTV_SOURCES_FILE=config/cctv_sources.shinjuku.json npm run dev
+```
+
+Or equivalently, via `./scripts/dev-cctv.sh`:
+
+```bash
+CCTV_SOURCES_FILE=config/cctv_sources.shinjuku.json ./scripts/dev-cctv.sh
+```
+
+The pack exercises the same CCTV registration and frustum-projection pipeline
+as live city packs without requiring network access to a camera catalog. It is
+**not** a live data source and carries no external attribution requirement. The
+sample videos are publicly available Google test media.
+
+`config/cctv_sources.austin.json` is the reference live pack. Custom source
+packs follow the same JSON schema (see either file); `CCTV_SOURCES_JSON`
+accepts inline JSON as an alternative to a file path.
+
 ---
 
 ## In-app attribution