refactor: split playback proxy logic into separate handler files

internal/playback/handler/proxy_token.go

@@ -0,0 +1,23 @@
+package handler
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+func (h *PlaybackHandler) resolveProxyRequestTarget(c *gin.Context, scope string) (string, string, bool) {
+	token := c.Query("token")
+	if token == "" {
+		c.Status(http.StatusBadRequest)
+		return "", "", false
+	}
+
+	targetURL, referer, err := h.svc.ResolveProxyToken(token, scope)
+	if err != nil {
+		c.Status(http.StatusForbidden)
+		return "", "", false
+	}
+
+	return targetURL, referer, true
+}