Improve odometry with rotation estimation, daemon stability, and RTSP fixes

- Add rotation estimation via log-polar phase correlation (EstimateRotation,
  rotateGray) — de-rotate before translation to avoid aliasing
- Track cumulative field rotation in Tracker, reject low-confidence frames
- Extract RTSP grabber into internal/rtspgrab module
- Daemon: pause odometry during slew (motion blur), auto-resume after settle
  delay, add /pause and /resume HTTP endpoints, switch shooting mode before
  opening camera, use ReqOpenCamera with rtsp_encode_type=1
- WebSocket heartbeat (ping/pong every 10s) to prevent idle disconnects
- FFmpeg low-latency flags (-fflags nobuffer, -probesize, -analyzeduration)
- Add SendRaw API for custom payloads, increase daemon HTTP timeout to 60s

💘 Generated with Crush

Assisted-by: Crush:/models/Qwen3.6-27B-uncensored-heretic-v2-Native-MTP-Preserved-Q4_K_M.gguf

dwarfctl/internal/transport/client.go

@@ -60,10 +60,41 @@ func (c *Client) Connect(ip string) error {
 		return fmt.Errorf("ws dial %s: %w", url, err)
 	}
 	c.conn = conn
+	// Keep the connection alive — the telescope closes idle connections
+	// after ~30s. The PongHandler also resets the read deadline on each pong.
+	conn.SetPingHandler(func(string) error {
+		conn.WriteControl(websocket.PongMessage, nil, time.Now().Add(5*time.Second))
+		return nil
+	})
 	go c.readLoop()
+	go c.heartbeatLoop()
 	return nil
 }
 
+// heartbeatLoop sends periodic ping frames to keep the WebSocket alive.
+// The telescope drops idle connections after ~30s.
+func (c *Client) heartbeatLoop() {
+	ticker := time.NewTicker(10 * time.Second)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-c.done:
+			return
+		case <-ticker.C:
+			c.mu.Lock()
+			if c.conn == nil {
+				c.mu.Unlock()
+				return
+			}
+			err := c.conn.WriteControl(websocket.PingMessage, nil, time.Now().Add(5*time.Second))
+			c.mu.Unlock()
+			if err != nil && c.Debug {
+				log.Printf("[WS] heartbeat ping error: %v", err)
+			}
+		}
+	}
+}
+
 // Close shuts down the connection.
 func (c *Client) Close() error {
 	close(c.done)