fix: clarify seedance reference video failures

docs/pending-test.md

@@ -1,6 +1,7 @@
 # 待测试
 
 - Docker 部署时，`DATABASE_DSN=data/infinite-canvas.db` 会在存在 `/app/data` 挂载目录时自动归一到 `/app/data/infinite-canvas.db`，需要验证后台模型配置不会再因为工作目录变为 `/app/web` 而读到空库。
+- Seedance 参考视频被火山判定包含真人或隐私信息时，前端错误摘要会提示改用不含真人的视频、官方允许的模型产物或已授权的 `asset://` 素材；参考素材上传目录改为跟随 SQLite 数据目录，并补充公开素材的 HEAD 访问。
 - Seedance 参考素材失败原因排查：后端会把火山上游错误摘要返回给前端；`/video` 和画布视频生成会按 `图片1/视频1/音频1` 自动编号参考素材，并在实际请求提示词中注入编号说明；参考视频会在请求前校验大小、时长、宽高、宽高比和像素总量。
 - 画布项目导出改为下载 `.zip` 压缩包，包内包含 `projects.json` 和当前画布引用到的本地图片、视频文件，避免只导出 JSON 时丢失媒体内容。
 - 画布库支持多选后一键导出多个画布项目，导出的压缩包可一次恢复多个项目。

handler/ai.go

@@ -263,6 +263,9 @@ func aiUpstreamErrorDetail(body []byte) string {
 	}
 	if err := json.Unmarshal(body, &payload); err == nil {
 		if payload.Error.Message != "" {
+			if detail := friendlyUpstreamError(payload.Error.Code, payload.Error.Message); detail != "" {
+				return safeUpstreamText(detail)
+			}
 			if payload.Error.Code != "" {
 				return safeUpstreamText(payload.Error.Code + " " + payload.Error.Message)
 			}
@@ -278,6 +281,14 @@ func aiUpstreamErrorDetail(body []byte) string {
 	return safeUpstreamText(text)
 }
 
+func friendlyUpstreamError(code string, message string) string {
+	lowerCode := strings.ToLower(strings.TrimSpace(code))
+	if strings.Contains(lowerCode, "inputvideosensitivecontentdetected") || strings.Contains(lowerCode, "privacyinformation") {
+		return strings.TrimSpace(code + " 参考视频疑似包含真人或隐私信息，火山方舟拒绝使用普通 URL 作为真人视频参考；请改用不含真人的视频、官方允许的模型产物，或已授权的 asset:// 素材。原始错误：" + message)
+	}
+	return ""
+}
+
 func safeUpstreamText(text string) string {
 	text = strings.Join(strings.Fields(strings.TrimSpace(text)), " ")
 	runes := []rune(text)

handler/ai_test.go

@@ -12,6 +12,13 @@ func TestAIUpstreamErrorDetail(t *testing.T) {
 	}
 }
 
+func TestAIUpstreamErrorDetailExplainsSensitiveVideo(t *testing.T) {
+	got := aiUpstreamErrorDetail([]byte(`{"error":{"code":"InputVideoSensitiveContentDetected.PrivacyInformation","message":"The request failed because the input video may contain real person."}}`))
+	if !strings.Contains(got, "参考视频疑似包含真人") || !strings.Contains(got, "asset://") {
+		t.Fatalf("detail = %q", got)
+	}
+}
+
 func TestSafeUpstreamTextTruncates(t *testing.T) {
 	got := safeUpstreamText(strings.Repeat("错", 320))
 	if len([]rune(got)) != 303 {

handler/media_reference.go

@@ -117,7 +117,25 @@ func ReferenceMedia(w http.ResponseWriter, r *http.Request, id string) {
 }
 
 func referenceMediaDir() string {
-	return filepath.Join("data", "reference-media")
+	return filepath.Join(referenceDataDir(), "reference-media")
+}
+
+func referenceDataDir() string {
+	driver := strings.ToLower(strings.TrimSpace(config.Cfg.StorageDriver))
+	dsn := strings.TrimSpace(config.Cfg.DatabaseDSN)
+	if (driver == "" || driver == "sqlite") && dsn != "" && dsn != ":memory:" && !strings.HasPrefix(dsn, "file:") {
+		pathPart := dsn
+		if index := strings.Index(dsn, "?"); index >= 0 {
+			pathPart = dsn[:index]
+		}
+		if filepath.IsAbs(pathPart) {
+			return filepath.Dir(pathPart)
+		}
+	}
+	if _, err := os.Stat("/app/data"); err == nil {
+		return "/app/data"
+	}
+	return "data"
 }
 
 func normalizeReferenceMediaType(contentType string, ext string) (string, string, bool) {

handler/media_reference_test.go

@@ -1,6 +1,11 @@
 package handler
 
-import "testing"
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/basketikun/infinite-canvas/config"
+)
 
 func TestNormalizeReferenceMediaTypeSupportsAudio(t *testing.T) {
 	tests := []struct {
@@ -38,3 +43,14 @@ func TestReferenceMediaTypeMaxBytes(t *testing.T) {
 		t.Fatalf("image max bytes = %d, want %d", got, referenceImageMaxBytes)
 	}
 }
+
+func TestReferenceMediaDirUsesAbsoluteSQLiteDataDir(t *testing.T) {
+	previous := config.Cfg
+	t.Cleanup(func() { config.Cfg = previous })
+	root := t.TempDir()
+	config.Cfg = config.Config{StorageDriver: "sqlite", DatabaseDSN: filepath.Join(root, "infinite-canvas.db")}
+
+	if got := referenceMediaDir(); got != filepath.Join(root, "reference-media") {
+		t.Fatalf("referenceMediaDir = %q", got)
+	}
+}

router/router.go

@@ -25,6 +25,9 @@ func New() *gin.Engine {
 	api.GET("/media/references/:id", func(c *gin.Context) {
 		handler.ReferenceMedia(c.Writer, c.Request, c.Param("id"))
 	})
+	api.HEAD("/media/references/:id", func(c *gin.Context) {
+		handler.ReferenceMedia(c.Writer, c.Request, c.Param("id"))
+	})
 	v1 := api.Group("/v1", middleware.UserAuth)
 	v1.POST("/images/generations", gin.WrapF(handler.AIImagesGenerations))
 	v1.POST("/images/edits", gin.WrapF(handler.AIImagesEdits))