feat(Sora): 直连生成并移除sora2api依赖

实现直连 Sora 客户端、媒体落地与清理策略\n更新网关与前端配置以支持 Sora 平台\n补齐单元测试与契约测试，新增 curl 测试脚本\n\n测试: go test ./... -tags=unit

backend/internal/handler/sora_gateway_handler.go

@@ -10,7 +10,9 @@ import (
 	"io"
 	"log"
 	"net/http"
+	"os"
 	"path"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"time"
@@ -31,9 +33,8 @@ type SoraGatewayHandler struct {
 	concurrencyHelper   *ConcurrencyHelper
 	maxAccountSwitches  int
 	streamMode          string
-	sora2apiBaseURL     string
 	soraMediaSigningKey string
-	mediaClient         *http.Client
+	soraMediaRoot       string
 }
 
 // NewSoraGatewayHandler creates a new SoraGatewayHandler
@@ -48,6 +49,7 @@ func NewSoraGatewayHandler(
 	maxAccountSwitches := 3
 	streamMode := "force"
 	signKey := ""
+	mediaRoot := "/app/data/sora"
 	if cfg != nil {
 		pingInterval = time.Duration(cfg.Concurrency.PingInterval) * time.Second
 		if cfg.Gateway.MaxAccountSwitches > 0 {
@@ -57,14 +59,9 @@ func NewSoraGatewayHandler(
 			streamMode = mode
 		}
 		signKey = strings.TrimSpace(cfg.Gateway.SoraMediaSigningKey)
-	}
-	baseURL := ""
-	if cfg != nil {
-		baseURL = strings.TrimRight(strings.TrimSpace(cfg.Sora2API.BaseURL), "/")
-	}
-	mediaTimeout := 180 * time.Second
-	if cfg != nil && cfg.Gateway.SoraRequestTimeoutSeconds > 0 {
-		mediaTimeout = time.Duration(cfg.Gateway.SoraRequestTimeoutSeconds) * time.Second
+		if root := strings.TrimSpace(cfg.Sora.Storage.LocalPath); root != "" {
+			mediaRoot = root
+		}
 	}
 	return &SoraGatewayHandler{
 		gatewayService:      gatewayService,
@@ -73,9 +70,8 @@ func NewSoraGatewayHandler(
 		concurrencyHelper:   NewConcurrencyHelper(concurrencyService, SSEPingFormatComment, pingInterval),
 		maxAccountSwitches:  maxAccountSwitches,
 		streamMode:          strings.ToLower(streamMode),
-		sora2apiBaseURL:     baseURL,
 		soraMediaSigningKey: signKey,
-		mediaClient:         &http.Client{Timeout: mediaTimeout},
+		soraMediaRoot:       mediaRoot,
 	}
 }
 
@@ -377,34 +373,24 @@ func (h *SoraGatewayHandler) errorResponse(c *gin.Context, status int, errType,
 	})
 }
 
-// MediaProxy proxies /tmp or /static media files from sora2api
+// MediaProxy serves local Sora media files.
 func (h *SoraGatewayHandler) MediaProxy(c *gin.Context) {
 	h.proxySoraMedia(c, false)
 }
 
-// MediaProxySigned proxies /tmp or /static media files with signature verification
+// MediaProxySigned serves local Sora media files with signature verification.
 func (h *SoraGatewayHandler) MediaProxySigned(c *gin.Context) {
 	h.proxySoraMedia(c, true)
 }
 
 func (h *SoraGatewayHandler) proxySoraMedia(c *gin.Context, requireSignature bool) {
-	if h.sora2apiBaseURL == "" {
-		c.JSON(http.StatusServiceUnavailable, gin.H{
-			"error": gin.H{
-				"type":    "api_error",
-				"message": "sora2api 未配置",
-			},
-		})
-		return
-	}
-
 	rawPath := c.Param("filepath")
 	if rawPath == "" {
 		c.Status(http.StatusNotFound)
 		return
 	}
 	cleaned := path.Clean(rawPath)
-	if !strings.HasPrefix(cleaned, "/tmp/") && !strings.HasPrefix(cleaned, "/static/") {
+	if !strings.HasPrefix(cleaned, "/image/") && !strings.HasPrefix(cleaned, "/video/") {
 		c.Status(http.StatusNotFound)
 		return
 	}
@@ -445,40 +431,25 @@ func (h *SoraGatewayHandler) proxySoraMedia(c *gin.Context, requireSignature boo
 			return
 		}
 	}
-
-	targetURL := h.sora2apiBaseURL + cleaned
-	if rawQuery := query.Encode(); rawQuery != "" {
-		targetURL += "?" + rawQuery
-	}
-
-	req, err := http.NewRequestWithContext(c.Request.Context(), c.Request.Method, targetURL, nil)
-	if err != nil {
-		c.Status(http.StatusBadGateway)
+	if strings.TrimSpace(h.soraMediaRoot) == "" {
+		c.JSON(http.StatusServiceUnavailable, gin.H{
+			"error": gin.H{
+				"type":    "api_error",
+				"message": "Sora 媒体目录未配置",
+			},
+		})
 		return
 	}
-	copyHeaders := []string{"Range", "If-Range", "If-Modified-Since", "If-None-Match", "Accept", "User-Agent"}
-	for _, key := range copyHeaders {
-		if val := c.GetHeader(key); val != "" {
-			req.Header.Set(key, val)
-		}
-	}
 
-	client := h.mediaClient
-	if client == nil {
-		client = http.DefaultClient
-	}
-	resp, err := client.Do(req)
-	if err != nil {
-		c.Status(http.StatusBadGateway)
+	relative := strings.TrimPrefix(cleaned, "/")
+	localPath := filepath.Join(h.soraMediaRoot, filepath.FromSlash(relative))
+	if _, err := os.Stat(localPath); err != nil {
+		if os.IsNotExist(err) {
+			c.Status(http.StatusNotFound)
+			return
+		}
+		c.Status(http.StatusInternalServerError)
 		return
 	}
-	defer func() { _ = resp.Body.Close() }()
-
-	for _, key := range []string{"Content-Type", "Content-Length", "Accept-Ranges", "Content-Range", "Cache-Control", "Last-Modified", "ETag"} {
-		if val := resp.Header.Get(key); val != "" {
-			c.Header(key, val)
-		}
-	}
-	c.Status(resp.StatusCode)
-	_, _ = io.Copy(c.Writer, resp.Body)
+	c.File(localPath)
 }