fix: remove redundant rollback, document asymmetry in cancellation notifications

backend/handlers/user/user_coverage_test.go

@@ -563,10 +563,8 @@ func TestDeleteAccount_WithProfilePicture(t *testing.T) {
 
 	// Handler returns 204 regardless of goroutine result
 	assert.Equal(t, http.StatusNoContent, w.Code)
-	// Allow goroutines to start before test cleanup
-	assert.Eventually(t, func() bool {
-		return true
-	}, 100*time.Millisecond, 10*time.Millisecond)
+	// Best-effort wait for background goroutine to initiate
+	time.Sleep(50 * time.Millisecond)
 }
 
 // =============================================================================
@@ -592,7 +590,7 @@ func TestDeleteAccount_WithSquareClient(t *testing.T) {
 	handler.ServeHTTP(w, req)
 
 	assert.Equal(t, http.StatusNoContent, w.Code)
-	assert.Eventually(t, func() bool {
-		return true
-	}, 100*time.Millisecond, 10*time.Millisecond)
+	// Best-effort wait for background goroutine to initiate
+	time.Sleep(50 * time.Millisecond)
 }
+