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

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

dwarfctl/internal/odometry/rotate.go

@@ -0,0 +1,53 @@
+package odometry
+
+import "math"
+
+// rotateGray rotates a grayscale matrix by angleDeg (positive = clockwise)
+// around its center, using bilinear interpolation. The output has the same
+// dimensions as the input.
+func rotateGray(g [][]float64, size int, angleDeg float64) [][]float64 {
+	theta := angleDeg * math.Pi / 180.0
+	cosT := math.Cos(theta)
+	sinT := math.Sin(theta)
+	cy := float64(size-1) / 2.0
+	cx := float64(size-1) / 2.0
+
+	out := make([][]float64, size)
+	for i := range out {
+		out[i] = make([]float64, size)
+	}
+
+	for oy := 0; oy < size; oy++ {
+		for ox := 0; ox < size; ox++ {
+			// Map output pixel to input coordinates via inverse rotation.
+			dy := float64(oy) - cy
+			dx := float64(ox) - cx
+			sx := cx + dx*cosT + dy*sinT
+			sy := cy - dx*sinT + dy*cosT
+
+			// Bilinear interpolation with clamp at borders.
+			x0 := int(math.Floor(sx))
+			y0 := int(math.Floor(sy))
+			fx := sx - float64(x0)
+			fy := sy - float64(y0)
+
+			x0 = clampInt(x0, 0, size-1)
+			y0 = clampInt(y0, 0, size-1)
+			x1 := clampInt(x0+1, 0, size-1)
+			y1 := clampInt(y0+1, 0, size-1)
+
+			out[oy][ox] = (1-fy)*(1-fx)*g[y0][x0] +
+				(1-fy)*fx*g[y0][x1] +
+				fy*(1-fx)*g[y1][x0] +
+				fy*fx*g[y1][x1]
+		}
+	}
+	return out
+}
+
+func absf(x float64) float64 {
+	if x < 0 {
+		return -x
+	}
+	return x
+}