Add light bar detector and detect_test

- traditional CV pipeline referencing jlu_vision_26:
  HSV mask -> contour LightBar -> PCA corner refine -> pairing gates
- big/small armor classification (bar distance / bar length ratio)
- detect_test with synthetic selftest, 6/6 passed
- measured armor size 131.56x55mm, solver NaN guard + ITERATIVE fallback

xmake.lua

@@ -30,6 +30,7 @@ target("27RM")
     remove_files("src/capture_calib.cpp")
     remove_files("src/calibrate.cpp")
     remove_files("src/pose_test.cpp")
+    remove_files("src/detect_test.cpp")
 
 -- 标定图采集工具
 --   ./build/linux/x86_64/debug/capture_calib              （MindVision 相机）
@@ -53,3 +54,13 @@ target("pose_test")
     add_rules("rm_deps")
     set_kind("binary")
     add_files("src/pose_test.cpp", "src/camera_calib.cpp", "src/camera_set.cpp")
+
+-- 灯条检测验证工具（检测 → 4 角点 → PnP → 距离/yaw/pitch）
+--   ./build/linux/x86_64/debug/detect_test              （相机实时）
+--   ./build/linux/x86_64/debug/detect_test --selftest   （合成自检，无需相机）
+--   ./build/linux/x86_64/debug/detect_test --image x.jpg --once
+target("detect_test")
+    add_rules("rm_deps")
+    set_kind("binary")
+    add_files("src/detect_test.cpp", "src/light_bar.cpp",
+              "src/camera_calib.cpp", "src/camera_set.cpp")