Initial commit: HC900 Crawler

Honeywell HC900을 Modbus TCP로 직접 폴링 → gRPC → C# 크롤러 → PostgreSQL.
기존 Experion OPC UA 데이터 경로를 HC900 직접 통신으로 대체.

- industrial-comm/cpp: C++ Modbus 게이트웨이 (gRPC 서버)
- src: C# .NET 8 ASP.NET Core 크롤러 + 웹 UI (3-Layer)
- mcp-server: Python FastMCP (RAG/NL2SQL/P&ID)
- 다중 컨트롤러(N-Controller) 지원

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

hc900crawler.service

@@ -0,0 +1,26 @@
+[Unit]
+Description=HC900 Crawler - Modbus to gRPC Web Service
+After=network-online.target docker.service
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=windpacer
+WorkingDirectory=/home/windpacer/projects/hc900_ax/src/Hc900Crawler
+
+# dotnet publish된 바이너리 사용 (권장) 또는 dotnet run
+ExecStart=/usr/bin/dotnet run
+
+Restart=always
+RestartSec=10
+
+# 로그
+StandardOutput=append:/tmp/hc900_crawler.log
+StandardError=append:/tmp/hc900_crawler.log
+
+# 환경변수
+Environment=DOTNET_ENVIRONMENT=Production
+Environment=ASPNETCORE_URLS=http://0.0.0.0:5000
+
+[Install]
+WantedBy=multi-user.target