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>

industrial-comm/cpp/include/gateway.h

@@ -0,0 +1,103 @@
+#ifndef HC900_GATEWAY_H
+#define HC900_GATEWAY_H
+
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <vector>
+#include <atomic>
+#include <thread>
+#include <mutex>
+#include <chrono>
+
+#include "modbus_gateway.grpc.pb.h"
+#include "modbus_gateway.pb.h"
+
+class Controller;
+
+struct RegisterEntry {
+    std::string tag;
+    uint32_t addr;
+    uint32_t count;   // register count (1 or 2)
+    std::string type; // "float32" or "uint16"
+    std::string access; // "R" or "RW"
+};
+
+struct CachedValue {
+    float float32_val;
+    uint32_t uint16_val;
+    bool is_float;
+    uint32_t quality; // 192=good, 0=bad
+    std::chrono::system_clock::time_point timestamp;
+};
+
+class Hc900Gateway final {
+public:
+    Hc900Gateway(const std::string& host, uint16_t port,
+                 const std::string& map_path,
+                 int poll_interval_ms = 1000,
+                 int grpc_port = 50051);
+    ~Hc900Gateway();
+
+    bool Start();
+    void Stop();
+
+private:
+    void PollLoop();
+    void LoadRegisterMap(const std::string& path);
+    void ReadAllRegisters();
+    CachedValue ReadRegister(const RegisterEntry& entry);
+
+    // gRPC service implementation
+    class GatewayServiceImpl final : public hc900::ModbusGateway::Service {
+    public:
+        GatewayServiceImpl(Hc900Gateway& gateway);
+        grpc::Status ReadTags(grpc::ServerContext* ctx,
+                              const hc900::ReadTagsRequest* req,
+                              hc900::ReadTagsResponse* resp) override;
+        grpc::Status WriteTag(grpc::ServerContext* ctx,
+                              const hc900::WriteTagRequest* req,
+                              hc900::WriteTagResponse* resp) override;
+        grpc::Status ListTags(grpc::ServerContext* ctx,
+                              const hc900::ListTagsRequest* req,
+                              hc900::ListTagsResponse* resp) override;
+        grpc::Status HealthCheck(grpc::ServerContext* ctx,
+                                  const hc900::HealthCheckRequest* req,
+                                  hc900::HealthCheckResponse* resp) override;
+        grpc::Status StreamTags(grpc::ServerContext* ctx,
+                                const hc900::StreamTagsRequest* req,
+                                grpc::ServerWriter<hc900::TagValue>* writer) override;
+    private:
+        Hc900Gateway& gateway_;
+    };
+
+    std::string host_;
+    uint16_t port_;
+    int poll_interval_ms_;
+    std::unique_ptr<Controller> controller_;
+
+    // Register map
+    std::vector<RegisterEntry> registers_;
+    std::unordered_map<std::string, size_t> tag_index_;
+    std::vector<size_t> sorted_indices_;  // indices into registers_, sorted by address
+
+    // Cache
+    std::unordered_map<std::string, CachedValue> cache_;
+    mutable std::mutex cache_mutex_;
+
+    // Transport — shared between poll thread and gRPC handlers
+    mutable std::mutex transport_mutex_;
+
+    // Poller
+    std::atomic<bool> running_;
+    std::thread poll_thread_;
+    uint64_t poll_count_{0};
+    std::chrono::milliseconds last_poll_duration_{0};
+
+    // gRPC server
+    std::unique_ptr<grpc::Server> grpc_server_;
+    std::unique_ptr<GatewayServiceImpl> grpc_service_;
+    std::string grpc_listen_;
+};
+
+#endif // HC900_GATEWAY_H