feat(gitea): read retry once on 5xx GET

internal/gitea/client_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"net/http"
 	"net/http/httptest"
+	"sync/atomic"
 	"testing"
 
 	"gitea.d-ma.be/mathias/gitea-mcp/internal/gitea"
@@ -27,3 +28,37 @@ func TestClientGetsTokenInHeader(t *testing.T) {
 	assert.Contains(t, string(body), `"ok":true`)
 	assert.Equal(t, "token test-token", gotAuth)
 }
+
+func TestRetryOn5xxGetSucceedsOnSecondAttempt(t *testing.T) {
+	var attempts int32
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		n := atomic.AddInt32(&attempts, 1)
+		if n == 1 {
+			http.Error(w, "boom", http.StatusServiceUnavailable)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"ok":true}`))
+	}))
+	defer srv.Close()
+
+	c := gitea.NewClient(srv.URL, "tok")
+	body, status, err := c.GetJSON(context.Background(), "/api/v1/test")
+	require.NoError(t, err)
+	assert.Equal(t, 200, status)
+	assert.Contains(t, string(body), `"ok":true`)
+	assert.Equal(t, int32(2), atomic.LoadInt32(&attempts))
+}
+
+func TestRetryOnPostNotRetried(t *testing.T) {
+	var attempts int32
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		atomic.AddInt32(&attempts, 1)
+		http.Error(w, "boom", http.StatusServiceUnavailable)
+	}))
+	defer srv.Close()
+
+	c := gitea.NewClient(srv.URL, "tok")
+	_, _, _ = c.PostJSON(context.Background(), "/api/v1/test", []byte(`{}`))
+	assert.Equal(t, int32(1), atomic.LoadInt32(&attempts), "POST should not retry")
+}