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>

scripts/build.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+BUILD_DIR="$ROOT_DIR/build"
+mkdir -p "$BUILD_DIR"
+
+CGO_ENABLED=0 GOOS=linux GOARCH=arm64 \
+  go build -o "$BUILD_DIR/edge-agent" "$ROOT_DIR/cmd/edge-agent"
+
+echo "built: $BUILD_DIR/edge-agent"