feat: impl config loading

apps/backend/cmd/drexa/main.go

@@ -1,19 +1,27 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"log"
+	"os"
 
 	"github.com/get-drexa/drexa/internal/drexa"
-	"github.com/joho/godotenv"
 )
 
 func main() {
-	_ = godotenv.Load()
+	configPath := flag.String("config", "", "path to config file (required)")
+	flag.Parse()
 
-	config, err := drexa.ServerConfigFromEnv()
+	if *configPath == "" {
+		fmt.Fprintln(os.Stderr, "error: --config is required")
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	config, err := drexa.ConfigFromFile(*configPath)
 	if err != nil {
-		log.Fatal(err)
+		log.Fatalf("failed to load config: %v", err)
 	}
 
 	server, err := drexa.NewServer(*config)
@@ -21,5 +29,6 @@ func main() {
 		log.Fatal(err)
 	}
 
-	log.Fatal(server.Listen(fmt.Sprintf(":%d", config.Port)))
+	log.Printf("starting server on :%d", config.Server.Port)
+	log.Fatal(server.Listen(fmt.Sprintf(":%d", config.Server.Port)))
 }