Initial fullstack project setup with Next.js 15, Gin, PostgreSQL and Docker Compose

- Frontend: Next.js 15 (App Router), Auth.js v5, shadcn/ui, MagicUI
- Backend: Go + Gin + GORM with layered architecture
- Auth: Local credentials login with optional Keycloak OAuth binding
- Admin: RBAC user management for admin role
- Dev: Docker Compose with hot reload for both frontend and backend
- Docker: 3-service orchestration (frontend, backend, postgres)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/internal/config/config.go

@@ -0,0 +1,38 @@
+package config
+
+import (
+	"os"
+
+	"github.com/joho/godotenv"
+)
+
+type Config struct {
+	DatabaseURL      string
+	ServerPort       string
+	ServerAPIURL     string
+	AuthSecret       string
+	KeycloakIssuer   string
+	KeycloakID       string
+	KeycloakSecret   string
+}
+
+func Load() *Config {
+	_ = godotenv.Load()
+
+	return &Config{
+		DatabaseURL:    getEnv("DATABASE_URL", "postgres://evan:evanpass@localhost:5432/evanpage?sslmode=disable"),
+		ServerPort:     getEnv("SERVER_PORT", "8080"),
+		ServerAPIURL:   getEnv("SERVER_API_URL", "http://localhost:8080"),
+		AuthSecret:     getEnv("AUTH_SECRET", ""),
+		KeycloakIssuer: getEnv("AUTH_KEYCLOAK_ISSUER", ""),
+		KeycloakID:     getEnv("AUTH_KEYCLOAK_ID", ""),
+		KeycloakSecret: getEnv("AUTH_KEYCLOAK_SECRET", ""),
+	}
+}
+
+func getEnv(key, fallback string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return fallback
+}