feat(config): 统一加载 .env 并强化本地启动脚本

backend/cmd/migrate-channel-model-price-tiers/main.go

@@ -12,6 +12,7 @@ import (
 	"strings"
 	"time"
 
+	"infinite-canvas/backend/internal/config"
 	"infinite-canvas/backend/internal/database"
 	"infinite-canvas/backend/internal/model"
 	"infinite-canvas/backend/internal/repository"
@@ -38,6 +39,7 @@ type familyPlan struct {
 }
 
 func main() {
+	config.LoadDotEnv()
 	apply := flag.Bool("apply", false, "创建系统模型价格档并切换当前前台目录版本")
 	flag.Parse()
 	db, err := database.Open(database.Config{Driver: "postgres", DSN: os.Getenv("DATABASE_URL"), DataDir: os.Getenv("CANVAS_BACKEND_DATA_DIR")})

backend/cmd/migrate-logical-model-families/main.go

@@ -12,6 +12,7 @@ import (
 	"strconv"
 	"strings"
 
+	"infinite-canvas/backend/internal/config"
 	"infinite-canvas/backend/internal/database"
 	"infinite-canvas/backend/internal/model"
 	"infinite-canvas/backend/internal/repository"
@@ -55,6 +56,7 @@ var familyDefinitions = []familyDefinition{
 }
 
 func main() {
+	config.LoadDotEnv()
 	apply := flag.Bool("apply", false, "写入模型家族并归档旧 SKU 目录项")
 	flag.Parse()
 

backend/cmd/migrate-schema/main.go

@@ -8,10 +8,12 @@ import (
 	"strings"
 
 	"infinite-canvas/backend/internal/canvas"
+	"infinite-canvas/backend/internal/config"
 	"infinite-canvas/backend/internal/database"
 )
 
 func main() {
+	config.LoadDotEnv()
 	command := "up"
 	if len(os.Args) > 1 {
 		command = strings.ToLower(strings.TrimSpace(os.Args[1]))

backend/cmd/migrate-sqlite-postgres/main.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 	"time"
 
+	"infinite-canvas/backend/internal/config"
 	"infinite-canvas/backend/internal/database"
 	"infinite-canvas/backend/internal/model"
 
@@ -22,6 +23,7 @@ type tableMigration struct {
 }
 
 func main() {
+	config.LoadDotEnv()
 	sourcePath := strings.TrimSpace(os.Getenv("SQLITE_SOURCE_PATH"))
 	targetDSN := strings.TrimSpace(os.Getenv("DATABASE_URL"))
 	if sourcePath == "" || targetDSN == "" {

backend/cmd/reseed-logical-model-sources/main.go

@@ -9,6 +9,7 @@ import (
 	"sort"
 	"strings"
 
+	"infinite-canvas/backend/internal/config"
 	"infinite-canvas/backend/internal/database"
 	"infinite-canvas/backend/internal/model"
 	"infinite-canvas/backend/internal/repository"
@@ -25,6 +26,7 @@ type sourcePlan struct {
 }
 
 func main() {
+	config.LoadDotEnv()
 	apply := flag.Bool("apply", false, "将符合条件的前台模型改为系统渠道模型驱动")
 	flag.Parse()
 

backend/cmd/server/main.go

@@ -15,6 +15,7 @@ import (
 	"syscall"
 	"time"
 
+	"infinite-canvas/backend/internal/config"
 	"infinite-canvas/backend/internal/database"
 	"infinite-canvas/backend/internal/handler"
 	"infinite-canvas/backend/internal/repository"
@@ -33,6 +34,8 @@ func main() {
 }
 
 func run(ctx context.Context) error {
+	// 先加载仓库根的 .env（若存在），再读取环境变量，保证直连 `go run` 也能读到配置。
+	config.LoadDotEnv()
 	dataDir := env("CANVAS_BACKEND_DATA_DIR", "data")
 	if err := os.MkdirAll(dataDir, 0o755); err != nil {
 		return err
@@ -48,6 +51,7 @@ func run(ctx context.Context) error {
 	if err := database.ConfigurePool(db); err != nil {
 		return err
 	}
+	log.Printf("database driver: %s (DATABASE_URL %s)", db.Dialector.Name(), map[bool]string{true: "set", false: "empty"}[strings.TrimSpace(os.Getenv("DATABASE_URL")) != ""])
 	sqlDB, err := db.DB()
 	if err != nil {
 		return err

backend/internal/config/dotenv.go

@@ -0,0 +1,83 @@
+// Package config 提供轻量的运行时配置辅助能力。
+//
+// 后端只从环境变量读取配置；为方便本地开发（不依赖启动脚本注入），
+// 这里提供一个零依赖的 .env 加载器，供 server / migrate-schema 等命令共用。
+package config
+
+import (
+	"bufio"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// LoadDotEnv 从若干候选路径读取 .env 并注入进程环境变量。
+//
+// 规则：
+//   - 已存在的环境变量优先，不会被覆盖（Docker/脚本注入的值始终生效）；
+//   - 跳过空行与 # 注释，兼容 export 前缀与首尾引号；
+//   - 找不到 .env 时静默跳过，不影响生产部署。
+func LoadDotEnv() {
+	path := findDotEnvPath()
+	if path == "" {
+		return
+	}
+	file, err := os.Open(path)
+	if err != nil {
+		return
+	}
+	defer file.Close()
+
+	log.Printf("已从 %s 加载 .env 配置（已存在的环境变量优先，不覆盖）", path)
+
+	scanner := bufio.NewScanner(file)
+	// 连接串可能较长，放宽单行上限
+	scanner.Buffer(make([]byte, 0, 64*1024), 1024*1024)
+
+	for scanner.Scan() {
+		line := strings.TrimPrefix(scanner.Text(), "\ufeff") // 去掉可能的 UTF-8 BOM
+		line = strings.TrimSpace(line)
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		line = strings.TrimSpace(strings.TrimPrefix(line, "export "))
+
+		idx := strings.IndexByte(line, '=')
+		if idx <= 0 {
+			continue
+		}
+		key := strings.TrimSpace(line[:idx])
+		value := strings.TrimSpace(line[idx+1:])
+		if len(value) >= 2 && value[0] == '"' && value[len(value)-1] == '"' {
+			value = value[1 : len(value)-1]
+		}
+		if key == "" {
+			continue
+		}
+		if _, exists := os.LookupEnv(key); exists {
+			continue
+		}
+		_ = os.Setenv(key, value)
+	}
+}
+
+// findDotEnvPath 依次查找：显式指定的 CANVAS_ENV_FILE、当前目录、上级目录、上上级目录。
+func findDotEnvPath() string {
+	if explicit := strings.TrimSpace(os.Getenv("CANVAS_ENV_FILE")); explicit != "" {
+		if info, err := os.Stat(explicit); err == nil && !info.IsDir() {
+			return explicit
+		}
+	}
+	candidates := []string{
+		".env",
+		filepath.Join("..", ".env"),
+		filepath.Join("..", "..", ".env"),
+	}
+	for _, candidate := range candidates {
+		if info, err := os.Stat(candidate); err == nil && !info.IsDir() {
+			return candidate
+		}
+	}
+	return ""
+}