Add camera calibration toolchain and armor pose solver

- capture_calib: capture calibration images (MindVision / USB) with a live
  quality gate (Laplacian sharpness, 3x3 coverage, board auto-detect)
- calibrate: batch intrinsics from calib_images/, writes configs/camera.yaml
- camera_calib: CameraCalib loader (intrinsics + distortion, cached
  undistort remap) and solvePose() via IPPE with a reprojection gate
- configs/camera.yaml: MV-SUA131GC intrinsics, RMS 0.483 px over 31 images,
  ruler-verified distance error < 2%
- xmake: three targets sharing an rm_deps rule, C++17
- gitignore: keep calibration photos/videos and generated
  compile_commands.json out of the repo

configs/camera.yaml

@@ -0,0 +1,37 @@
+%YAML:1.0
+---
+# ============================================================
+# 相机标定与内参配置（27RM）
+# 本文件由 ./build/.../calibrate 生成，也可手工维护
+# ⚠️ M12 镜头的【对焦环位置】会改变有效焦距：
+#    一旦调焦，必须重新标定并重新做卷尺距离验证！
+# ============================================================
+camera_name: "MV-SUA131GC"
+lens: "MV-LD-M12-2.8MM-C"
+sensor: "1/3\" CMOS, 3.75um pixel"
+resolution: "1280x1024"
+calib_date: "2026-09-15"
+board_spec: "10x7 inner corners, square=20.0mm"
+calib_images: "31 (old_run 12 + new 19)"
+distance_verify: "ruler 700mm -> computed 687~697mm, error <2%"
+notes: "refocus invalidates this calibration; must re-verify with ruler"
+
+camera_matrix: !!opencv-matrix
+   rows: 3
+   cols: 3
+   dt: d
+   data: [ 657.47392591548282, 0., 625.64119358041364, 0.,
+       658.25468859263844, 509.00483710801581, 0., 0., 1. ]
+dist_coeffs: !!opencv-matrix
+   rows: 1
+   cols: 5
+   dt: d
+   data: [ -0.0012152502343767638, -0.058463444062878803,
+       -0.0022603001279860352, 0.0018169600148664874,
+       0.040233970225725772 ]
+image_width: 1280
+image_height: 1024
+square_mm: 20.
+board_cols: 10
+board_rows: 7
+rms: 0.48277734002307909