Add camera streaming guide with all access methods

Comprehensive documentation for accessing the DWARF camera streams:
- RTSP URLs and channels (ch0=tele, ch1=wide)
- The critical prerequisite: camera must be opened via WebSocket first
- ffmpeg commands for frame capture, timelapse, and video recording
- mpv and VLC usage with TCP transport
- Python/OpenCV integration example
- Troubleshooting common issues (black image, connection refused, VLC delay)
- Comparison of RTSP vs MJPEG modes across device models

💘 Generated with Crush

Assisted-by: Crush:glm-5.2

analysis/API_REFERENCE.md

@@ -98,6 +98,34 @@ rtsp://<telescope_ip>:554/<channel>/stream0
 - Codec: MJPEG over RTSP (not H.264).
 - Port 8092 (MJPEG HTTP `/mainstream` and `/secondstream`) exists but is **inactive** on the DWARF Mini — the Mini uses RTSP exclusively.
 
+### 2.4 Visual odometry (image-based orientation)
+
+The wide-angle RTSP frames can be used to estimate the telescope's pointing
+rotation **without star identification or plate solving**, by comparing
+consecutive frames with FFT phase correlation. This is implemented in
+`dwarfctl` as the `orient` command (`internal/odometry/`).
+
+**Principle:** for small rotations of a static mount, the scene undergoes an
+almost pure 2-D translation in the image plane. Phase correlation recovers that
+translation with sub-pixel accuracy, which maps directly to pan/tilt degrees via
+the camera field of view. Accumulating frame-to-frame shifts gives cumulative
+pointing orientation.
+
+**Use cases on the DWARF Mini:**
+- **Daytime airplane tracking** — the wide cam provides sky/horizon texture
+- **Nighttime satellite tracking** — star fields serve as correlation texture
+
+**Pipeline:**
+1. Open the wide camera (`CMD_CAMERA_WIDE_OPEN_CAMERA` 12000) — or let `orient
+   live` do it automatically
+2. Grab frames via `ffmpeg -rtsp_transport tcp -i rtsp://<ip>/ch1/stream0`
+3. Compare consecutive frames (`Estimate`) or integrate continuously (`Tracker`)
+
+**FoV caveat:** the DWARF Mini's display FoV is 8.0°×6.5° (see
+`DEVICE_MODELS.md`), but the firmware-reported live FoV can differ. The pixel
+shift is always correct; only the degree conversion depends on the FoV
+parameter. Calibrate by slewing a known motor angle and comparing.
+
 ---
 
 ## 3. Wire format — `WsPacket` envelope