feat: migrate backend from rust to go

This commit replaces the Axum/Rust backend with a Gin/Go implementation. The original Rust code has been archived in the 'rust' branch.

cmd/llm-proxy/main.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"log"
+
+	"llm-proxy/internal/config"
+	"llm-proxy/internal/db"
+	"llm-proxy/internal/server"
+
+	"github.com/joho/godotenv"
+)
+
+func main() {
+	// Load environment variables
+	if err := godotenv.Load(); err != nil {
+		log.Println("No .env file found")
+	}
+
+	// Load configuration
+	cfg, err := config.Load()
+	if err != nil {
+		log.Fatalf("Failed to load configuration: %v", err)
+	}
+
+	// Initialize database
+	database, err := db.Init(cfg.Database.Path)
+	if err != nil {
+		log.Fatalf("Failed to initialize database: %v", err)
+	}
+
+	// Initialize server
+	s := server.NewServer(cfg, database)
+
+	// Run server
+	log.Printf("Starting LLM Proxy on %s:%d", cfg.Server.Host, cfg.Server.Port)
+	if err := s.Run(); err != nil {
+		log.Fatalf("Server failed: %v", err)
+	}
+}