Rename customs-tablet-frontend to public-frontend and add new features

- Rename customs-tablet-frontend/ to public-frontend/ for broader scope
- Add new pages: customs, inspection with camera integration
- Add new services: apiClient.ts, backendApi.ts, normalizers.ts
- Add CameraFrame component for real-time video streaming
- Add scan_fixer module with clock_publisher and timestamp fix utilities
- Update startup scripts to support new frontend structure
- Update arm_server configuration and service files

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scan_fixer/clock_publisher.py

@@ -0,0 +1,68 @@
+#!/usr/bin/env python3
+"""系统时钟发布器。
+
+向 /clock 持续发布系统时间，配合 Nav2 的 use_sim_time 配置，避免 AGV
+节点、雷达节点和导航栈之间出现时间源不一致。
+"""
+import os
+import sys
+
+import rclpy
+from rclpy.node import Node
+from rosgraph_msgs.msg import Clock
+
+
+LOCKFILE = "/tmp/clock_publisher.lock"
+PUBLISH_INTERVAL_SECONDS = 0.01
+LOG_INTERVAL_COUNT = 1000
+
+
+def ensure_single_instance(lockfile: str) -> None:
+    if os.path.exists(lockfile):
+        with open(lockfile) as f:
+            old_pid = int(f.read().strip())
+        try:
+            os.kill(old_pid, 0)
+            print(f"Another clock_publisher running PID {old_pid}, exit.", file=sys.stderr)
+            sys.exit(1)
+        except (OSError, ProcessLookupError):
+            print(f"Stale lock removed (PID {old_pid} dead)", file=sys.stderr)
+
+    with open(lockfile, "w") as f:
+        f.write(str(os.getpid()))
+
+
+class SystemClockPublisher(Node):
+    def __init__(self):
+        super().__init__("system_clock_publisher")
+        self.publisher = self.create_publisher(Clock, "/clock", 10)
+        self.timer = self.create_timer(PUBLISH_INTERVAL_SECONDS, self.publish_clock)
+        self.count = 0
+        self.get_logger().info(f"Clock publisher PID={os.getpid()}, publishing at 100Hz")
+
+    def publish_clock(self):
+        message = Clock()
+        message.clock = self.get_clock().now().to_msg()
+        self.publisher.publish(message)
+        self.count += 1
+        if self.count % LOG_INTERVAL_COUNT == 0:
+            self.get_logger().info(f"Published {self.count} clock messages")
+
+
+def main():
+    ensure_single_instance(LOCKFILE)
+    rclpy.init(args=sys.argv[1:])
+    node = SystemClockPublisher()
+    try:
+        rclpy.spin(node)
+    except KeyboardInterrupt:
+        pass
+    finally:
+        node.destroy_node()
+        rclpy.shutdown()
+        if os.path.exists(LOCKFILE):
+            os.remove(LOCKFILE)
+
+
+if __name__ == "__main__":
+    main()