fix: OpenList metadata download using API instead of WebDAV

OpenList 同步目录下载元数据（nfo/jpg/png/srt 等）全部失败，错误 http 401。

根因：Resolve() 中非视频文件走 WebDAV 直接下载，用 API token 作为 Authorization。
但 AList WebDAV 端点不接受 API token 认证，需要 Basic Auth。

修复：OpenList 在有 apiBase 时，所有文件都走 API /api/fs/get 获取直链，
不再走 WebDAV。API 失败时非视频文件可回退到 WebDAV。

影响范围：
- 只影响 OpenList 类型的非视频文件下载
- 不影响 115、CloudDrive2 等其他网盘
- 不影响视频播放/strm 生成

internal/service/cloud/clouddrive2.go

@@ -87,15 +87,15 @@ func (p *cloudDrive2Provider) Resolve(ctx context.Context, fileRef string) (*Dir
 	if ref == "/" {
 		return nil, fmt.Errorf("%s: file reference required", p.name)
 	}
-	if p.typ == TypeOpenList && isCloudVideoPlaybackCandidate(ref) {
-		if p.apiBase == nil {
-			return nil, fmt.Errorf("%s: pure 302 playback requires an OpenList API server address; configure server/api_url so /api/fs/get can return raw_url", p.name)
-		}
+	if p.typ == TypeOpenList && p.apiBase != nil {
 		link, err := p.resolveOpenListAPIDirect(ctx, ref)
-		if err != nil {
-			return nil, fmt.Errorf("%s: pure 302 playback requires OpenList raw_url for %s: %w", p.name, ref, err)
+		if err == nil {
+			return link, nil
+		}
+		// API 获取直链失败：非视频文件（元数据）回退到 WebDAV；视频文件报错
+		if isCloudVideoPlaybackCandidate(ref) {
+			return nil, fmt.Errorf("%s: resolve download URL for %s via API failed: %w", p.name, ref, err)
 		}
-		return link, nil
 	}
 	if p.typ == TypeCloudDrive2 && isCloudVideoPlaybackCandidate(ref) {
 		link, err := p.resolveCloudDAVRedirectDirect(ctx, ref)

internal/service/cloud/openlist_list_test.go

@@ -61,9 +61,10 @@ func TestOpenListWebDAVListAndResolve(t *testing.T) {
 	if len(entries) != 1 || entries[0].ID != "/Cloud/Movie.mkv" || entries[0].Size != 1024 {
 		t.Fatalf("entries = %#v", entries)
 	}
+	// Video file: API fails → error (no WebDAV fallback for video)
 	_, err = p.Resolve(context.Background(), entries[0].ID)
-	if err == nil || !strings.Contains(err.Error(), "pure 302 playback requires OpenList raw_url") {
-		t.Fatalf("openlist video resolve should require raw_url instead of WebDAV proxy fallback, err=%v", err)
+	if err == nil || !strings.Contains(err.Error(), "resolve download URL") || !strings.Contains(err.Error(), "via API failed") {
+		t.Fatalf("openlist video resolve should error on API failure, err=%v", err)
 	}
 }
 

internal/service/cloud/openlist_resolve_test.go

@@ -195,10 +195,43 @@ func TestOpenListResolveDoesNotFallbackToWebDAVWhenAPIRawURLFails(t *testing.T)
 		t.Fatal(err)
 	}
 	_, err = p.Resolve(context.Background(), "/Cloud/Movie.mkv")
-	if err == nil || !strings.Contains(err.Error(), "pure 302 playback requires OpenList raw_url") {
-		t.Fatalf("resolve error = %v, want raw_url requirement", err)
+	if err == nil || !strings.Contains(err.Error(), "resolve download URL") || !strings.Contains(err.Error(), "via API failed") {
+		t.Fatalf("resolve error = %v, want API resolve failure", err)
 	}
 	if davSeen {
 		t.Fatal("openlist video resolve fell back to WebDAV after raw_url failure")
 	}
 }
+
+func TestOpenListResolveMetadataUsesAPIInsteadOfWebDAV(t *testing.T) {
+	var gotPath, gotAuth string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotPath = r.URL.Path
+		gotAuth = r.Header.Get("Authorization")
+		if r.Method != http.MethodPost || r.URL.Path != "/api/fs/get" {
+			t.Fatalf("unexpected request %s %s; metadata should use API, not WebDAV", r.Method, r.URL.Path)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"code":200,"data":{"raw_url":"https://cdn.example.test/poster.jpg?sign=1"}}`))
+	}))
+	defer srv.Close()
+
+	p, err := New(TypeOpenList, map[string]any{"server": srv.URL, "token": "alist-token"}, srv.Client())
+	if err != nil {
+		t.Fatal(err)
+	}
+	// .nfo metadata file should use API, not WebDAV
+	link, err := p.Resolve(context.Background(), "/Cloud/Movie/Movie.nfo")
+	if err != nil {
+		t.Fatalf("resolve: %v", err)
+	}
+	if gotPath != "/api/fs/get" {
+		t.Fatalf("api path = %q, want /api/fs/get (metadata should not use WebDAV)", gotPath)
+	}
+	if gotAuth != "alist-token" {
+		t.Fatalf("Authorization = %q, want token", gotAuth)
+	}
+	if link.URL != "https://cdn.example.test/poster.jpg?sign=1" {
+		t.Fatalf("url = %q", link.URL)
+	}
+}