init: tianyan-edge edge agent with Ascend NPU inference backend

- Go main process: stream ingestor, infer client, event uploader,
  heartbeat, config agent, OTA agent
- Python inference server rewritten to use CANN ACL (acl module)
  replacing ultralytics/PyTorch; supports YOLOv8 raw and YOLOv10
  NMS-free output formats via OUTPUT_FORMAT env var
- systemd services for edge-agent and edge-infer
- build/install/package scripts targeting arm64

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

.env.template

@@ -0,0 +1,10 @@
+EDGE_ID=edge-demo-001
+CLOUD_URL=http://localhost:8004
+EDGE_TOKEN=
+
+# 多路用逗号分隔，留空则使用合成演示流
+RTSP_URLS=
+
+YOLO_MODEL=yolov8n.pt
+INFER_FPS=5
+CONF_THRESHOLD=0.5