fix: extend proxy timeout for Office rendering

internal/api/runtime.go

@@ -535,6 +535,27 @@ func (a *API) runtimeOriginAllowed(r *http.Request) bool {
 
 var runtimeTransport = &http.Transport{Proxy: nil, DialContext: (&net.Dialer{Timeout: 10 * time.Second, KeepAlive: 30 * time.Second}).DialContext, ResponseHeaderTimeout: 20 * time.Second, IdleConnTimeout: 90 * time.Second}
 
+// Office rendering can take longer than the normal API header deadline (the
+// bundled converter defaults to 60 seconds). Reuse a separate connection pool
+// without extending authentication or unrelated runtime requests.
+var runtimeOfficeTransport = func() *http.Transport {
+	t := runtimeTransport.Clone()
+	t.ResponseHeaderTimeout = 120 * time.Second
+	return t
+}()
+
+type runtimeProxyTransport struct {
+	normal, office http.RoundTripper
+}
+
+func (t runtimeProxyTransport) RoundTrip(r *http.Request) (*http.Response, error) {
+	// ReverseProxy has already removed the instance prefix here.
+	if r.URL.Path == "/api/officeToPdf/render" {
+		return t.office.RoundTrip(r)
+	}
+	return t.normal.RoundTrip(r)
+}
+
 type runtimeAuthKey struct {
 	api *API
 	id  string
@@ -1016,7 +1037,7 @@ func withoutRuntimeToken(rawQuery string) string {
 
 func runtimeReverseProxy(target *url.URL, prefix, host, cookies string) *httputil.ReverseProxy {
 	return &httputil.ReverseProxy{
-		Transport: runtimeTransport, FlushInterval: -1, ErrorLog: log.New(io.Discard, "", 0),
+		Transport: runtimeProxyTransport{normal: runtimeTransport, office: runtimeOfficeTransport}, FlushInterval: -1, ErrorLog: log.New(io.Discard, "", 0),
 		Rewrite: func(p *httputil.ProxyRequest) {
 			p.SetURL(target)
 			p.Out.Host = host