MVP: 按 07 风格重写前端 + Go 后端落地（长文/短文、编辑器、后台管理）

backend/internal/config/config.go

@@ -0,0 +1,87 @@
+package config
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+type Config struct {
+	Addr        string
+	Driver      string // sqlite | postgres
+	DSN         string
+	AdminUser   string
+	AdminPass   string
+	SessionSec  string
+	WebDist     string
+	DataDir     string
+	SiteURL     string
+	InsecureDev bool
+}
+
+func getenv(k, def string) string {
+	if v := strings.TrimSpace(os.Getenv(k)); v != "" {
+		return v
+	}
+	return def
+}
+
+func Load() (*Config, error) {
+	root := getenv("ONE_ROOT", "")
+	if root == "" {
+		if wd, err := os.Getwd(); err == nil {
+			root = filepath.Dir(wd) // server/ -> repo root
+		} else {
+			root = "."
+		}
+	}
+
+	c := &Config{
+		Addr:       getenv("ONE_ADDR", ":8080"),
+		Driver:     strings.ToLower(getenv("ONE_DB_DRIVER", "sqlite")),
+		AdminUser:  getenv("ONE_ADMIN_USER", "admin"),
+		AdminPass:  getenv("ONE_ADMIN_PASSWORD", "admin"),
+		SessionSec: getenv("ONE_SECRET", ""),
+		WebDist:    getenv("ONE_WEB_DIST", filepath.Join(root, "frontend", "dist")),
+		DataDir:    getenv("ONE_DATA_DIR", filepath.Join(root, "data")),
+		SiteURL:    getenv("ONE_SITE_URL", "http://localhost:8080"),
+	}
+
+	if c.Driver == "" {
+		c.Driver = "sqlite"
+	}
+	if c.Driver != "sqlite" && c.Driver != "postgres" && c.Driver != "postgresql" {
+		return nil, &badDriver{c.Driver}
+	}
+	if c.Driver == "postgresql" {
+		c.Driver = "postgres"
+	}
+
+	if c.DSN = getenv("ONE_DB_DSN", ""); c.DSN == "" {
+		if c.Driver == "sqlite" {
+			c.DSN = filepath.Join(c.DataDir, "one.db")
+		} else {
+			c.DSN = "postgres://localhost/one?sslmode=disable"
+		}
+	}
+
+	if c.SessionSec == "" {
+		b := make([]byte, 32)
+		if _, err := rand.Read(b); err != nil {
+			return nil, err
+		}
+		c.SessionSec = hex.EncodeToString(b)
+	}
+
+	c.InsecureDev = os.Getenv("ONE_ADMIN_PASSWORD") == ""
+
+	return c, nil
+}
+
+type badDriver struct{ d string }
+
+func (e *badDriver) Error() string {
+	return "unsupported ONE_DB_DRIVER: " + e.d + " (use sqlite or postgres)"
+}