Refactor lidar library: rename olei_config to lidar_config, add nanoscan example and shared byte helpers

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

examples/nanoscan_example.cpp

@@ -0,0 +1,37 @@
+// SICK nanoScan3 example. The sensor's UDP output target must be configured
+// in SICK Safety Designer; this driver only binds a local UDP port.
+#include "lidarlib/sick_lidar.hpp"
+#include <cstdio>
+
+int main() {
+    lidarlib::NanoScanDriver drv(lidarlib::MODEL_SICK_NANOSCAN3, "0.0.0.0", 6060);
+
+    if (!drv.open()) {
+        fprintf(stderr, "Không mở được UDP socket cho nanoScan3\n");
+        return 1;
+    }
+
+    for (int i = 0; i < 10; ++i) {
+        lidarlib::ScanResult result;
+        if (!drv.recv_scan(result, 2000)) {
+            fprintf(stderr, "Timeout hoặc lỗi nhận UDP datagram\n");
+            break;
+        }
+        const lidarlib::LaserScan& scan = result.scan;
+        const lidarlib::ExtraInfo& info = result.info;
+        printf("Scan #%d: %zu điểm, ts=%u, model=%s\n",
+               i, scan.ranges.size(), scan.timestamp_ms, info.detected_model.c_str());
+
+        for (size_t j = 0; j < 20 && j < scan.ranges.size(); ++j) {
+            float angle_deg = (scan.angle_min + j * scan.angle_increment) * 180.f / 3.14159265f;
+            printf("  [%zu] angle=%.2f° dist=%.3fm intensity=%.0f\n",
+                   j, angle_deg, scan.ranges[j], scan.intensities[j]);
+        }
+    }
+
+    drv.close();
+    return 0;
+}
+
+// Build:
+//   g++ -std=c++17 -O2 -Iinclude -o nanoscan_example examples/nanoscan_example.cpp src/sick_lidar.cpp