chore: rebrand project to GopherGate

Updated all naming from LLM Proxy to GopherGate. Implemented new CSS-based branding and updated Go module/binary naming.

cmd/gophergate/main.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"flag"
+	"log"
+	"os"
+
+	"gophergate/internal/config"
+	"gophergate/internal/db"
+	"gophergate/internal/server"
+
+	"github.com/joho/godotenv"
+	"golang.org/x/crypto/bcrypt"
+)
+
+func main() {
+	resetAdmin := flag.Bool("reset-admin", false, "Reset admin password to admin123")
+	flag.Parse()
+
+	// 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)
+	}
+
+	if *resetAdmin {
+		hash, _ := bcrypt.GenerateFromPassword([]byte("admin123"), 12)
+		_, err = database.Exec("UPDATE users SET password_hash = ?, must_change_password = 1 WHERE username = 'admin'", string(hash))
+		if err != nil {
+			log.Fatalf("Failed to reset admin password: %v", err)
+		}
+		log.Println("Admin password has been reset to 'admin123'")
+		os.Exit(0)
+	}
+
+	// Initialize server
+	s := server.NewServer(cfg, database)
+
+	// Run server
+	log.Printf("Starting GopherGate on %s:%d", cfg.Server.Host, cfg.Server.Port)
+	if err := s.Run(); err != nil {
+		log.Fatalf("Server failed: %v", err)
+	}
+}