Fix DHCP client unable to get IP and config not persisting

- Fixed verifyAssignment being too strict for new clients
- Fixed parseRequestedIP string conversion bug
- Fixed response sent to 0.0.0.0 instead of broadcast address
- Added SO_BROADCAST support for UDP socket
- Fixed session persistence after page refresh (localStorage)
- Added in-memory session store for auth middleware
- Added config reloader so DHCP server picks up web UI changes dynamically

cmd/main.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"flag"
+	"log"
+	"dhcp-dns-manager/internal/config"
+	"dhcp-dns-manager/internal/db"
+	"dhcp-dns-manager/internal/dhcp"
+	"dhcp-dns-manager/internal/dns"
+	"dhcp-dns-manager/internal/web"
+)
+
+func main() {
+	configPath := flag.String("config", "configs/config.json", "Path to configuration file")
+	flag.Parse()
+
+	// Load configuration
+	cfg, err := config.LoadConfig(*configPath)
+	if err != nil {
+		log.Fatalf("Failed to load config: %v", err)
+	}
+
+	// Initialize database
+	database, err := db.InitDB(cfg.Database.Path)
+	if err != nil {
+		log.Fatalf("Failed to initialize database: %v", err)
+	}
+
+	// Initialize DHCP server
+	dhcpServer := dhcp.NewServer(&cfg.DHCP, database)
+	if err := dhcpServer.Start(); err != nil {
+		log.Printf("Warning: DHCP server failed to start: %v", err)
+	} else {
+		log.Println("DHCP server started")
+	}
+
+	// Initialize DNS server
+	dnsServer := dns.NewServer(&cfg.DNS, database)
+	if err := dnsServer.Start(); err != nil {
+		log.Printf("Warning: DNS server failed to start: %v", err)
+	} else {
+		log.Println("DNS server started")
+	}
+
+	// Initialize Config Manager
+	configManager, err := web.NewConfigManager(*configPath)
+	if err != nil {
+		log.Fatalf("Failed to initialize config manager: %v", err)
+	}
+
+	// Initialize Web server
+	webServer := web.NewServer(&cfg.Web, database, dhcpServer, dnsServer, configManager)
+	log.Printf("Starting web interface on %s:%d", cfg.Web.Host, cfg.Web.Port)
+	if err := webServer.Start(); err != nil {
+		log.Fatalf("Web server failed to start: %v", err)
+	}
+}