Initialize CMS application scaffold

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

internal/config/config.go

@@ -0,0 +1,29 @@
+package config
+
+import (
+	"os"
+	"time"
+)
+
+type Config struct {
+	HTTPAddr, DatabaseURL, AllowedOrigins, GoogleClientID, GoogleClientSecret, GoogleRedirectURL string
+	SessionTTL                                                                                   time.Duration
+}
+
+func Load() Config {
+	return Config{HTTPAddr: get("CMS_HTTP_ADDR", ":8080"), DatabaseURL: get("CMS_DATABASE_URL", "./cms.db"), AllowedOrigins: get("CMS_ALLOWED_ORIGINS", "http://localhost:5173"), SessionTTL: duration("CMS_SESSION_TTL", 24*time.Hour), GoogleClientID: os.Getenv("CMS_GOOGLE_CLIENT_ID"), GoogleClientSecret: os.Getenv("CMS_GOOGLE_CLIENT_SECRET"), GoogleRedirectURL: os.Getenv("CMS_GOOGLE_REDIRECT_URL")}
+}
+func get(k, d string) string {
+	if v := os.Getenv(k); v != "" {
+		return v
+	}
+	return d
+}
+func duration(k string, d time.Duration) time.Duration {
+	if v := os.Getenv(k); v != "" {
+		if n, e := time.ParseDuration(v); e == nil {
+			return n
+		}
+	}
+	return d
+}