chore: WIP pre-implement

Co-authored-by: Cursor <cursoragent@cursor.com>

_docs/00_problem/input_data/flight_derkachi/README.md

@@ -12,3 +12,31 @@
 Use this fixture for video/telemetry synchronization checks, representative replay smoke tests, VIO hot-path latency, frame-drop accounting, and trajectory comparison against `GLOBAL_POSITION_INT`. The video and telemetry align at exactly three video frames per telemetry row. Camera intrinsics, lens distortion, raw camera resolution, and exact camera-to-body calibration are still unknown, so this fixture is not sufficient by itself for final production camera calibration or satellite-anchor accuracy claims.
 
 For the test recording, the rotating camera was mechanically fixed in a downward/nadir orientation. Treat the MP4 as a cleaned/cropped replay fixture rather than the raw camera feed.
+
+## Derkachi C6 reference seeding (cycle 3 — AZ-777 + Epic AZ-835)
+
+The end-to-end replay pipeline needs the C6 tile cache pre-populated with the satellite imagery that covers this flight. The seed scripts live under `tests/fixtures/derkachi_c6/`:
+
+| Script | Purpose |
+|--------|---------|
+| `tests/fixtures/derkachi_c6/seed_region.py` (AZ-777 Phase 2) | Bbox-driven seed. Calls `POST /api/satellite/request` on the running `satellite-provider` to onboard the Derkachi area (~50.05–50.15 lat, 36.05–36.15 lon, zoom 15–18). Companion to the existing bbox-download workflow. |
+| `tests/fixtures/derkachi_c6/seed_route.py` (AZ-838 / Epic AZ-835 C2) | Route-driven seed. Reads `derkachi.tlog`, extracts a ≤ 10-waypoint corridor via `replay_input.tlog_route.extract_route_from_tlog`, posts it to `satellite-provider`'s Route API, polls until `mapsReady=true`, and verifies coverage via inventory. ~100× more tile-efficient than the bbox path for this clip. |
+| `tests/fixtures/derkachi_c6/bbox.yaml` | Derkachi bbox + zoom levels + license-attribution metadata (Google Maps Platform ToS + "Imagery © Google" attribution string). |
+| `tests/fixtures/derkachi_c6/README.md` | Step-by-step re-seeding instructions when the `satellite-provider` postgres is wiped; license-attribution operators must propagate; pointer to the parent-suite ticket (TBD) for migrating to a true CC-BY satellite source for production. |
+
+Both seed scripts require:
+
+- A running `satellite-provider` reachable at `SATELLITE_PROVIDER_URL` (typically `https://satellite-provider:8080` inside the Jetson compose network).
+- A valid JWT — either `SATELLITE_PROVIDER_API_KEY` env var or `--auto-mint-jwt` (uses `scripts/mint_dev_jwt.py`).
+- `SATELLITE_PROVIDER_TLS_INSECURE=1` if the parent suite is using the self-signed dev cert (development only — production deploys must validate against a CA-issued cert).
+
+The end-to-end orchestrator test `tests/e2e/replay/test_az835_e2e_real_flight.py` (AZ-840) takes only `(derkachi.tlog, flight_derkachi.mp4, khp20s30_factory.json)` and runs the full 7-step pipeline against a populated C6 — see `_docs/02_document/contracts/replay/replay_protocol.md` Invariant 12.b for the orchestration.
+
+### License attribution caveat (cycle 3)
+
+The Jetson `satellite-provider` instance downloads from the **Google Maps satellite layer** (`lyrs=s`), governed by Google Maps Platform Terms of Service. This fixture and the seed scripts are dev/research use only. Production deployment requires either:
+
+- Google Maps Platform licensing review for offline-cache use, OR
+- A parent-suite ticket to switch satellite-provider's upstream to a true CC-BY satellite source (Esri World Imagery, Mapbox satellite, Sentinel-2, etc.).
+
+The "Imagery © Google" attribution string is recorded in the seeded catalog's metadata and must be propagated downstream by any operator workflow that surfaces the imagery.