diff --git a/.gitea/workflows/runner-image.yml b/.gitea/workflows/runner-image.yml
index 485eaee2..9ca7ddb0 100644
--- a/.gitea/workflows/runner-image.yml
+++ b/.gitea/workflows/runner-image.yml
@@ -18,8 +18,10 @@ on:
   workflow_dispatch:
 
 concurrency:
-  group: qemu                     # every workflow shares this one group (Captain Bob, 2026-11-07: a
-  cancel-in-progress: false       # runner-image rebuild blocks other jobs, always): one run at a time
+  group: qemu                     # every workflow shares this one group (2026-11-07: a runner-image
+  cancel-in-progress: false       # rebuild blocks other jobs, always): one run at a time; nothing
+                                  # cancelled -- runner.capacity: 1 explicit in config.yaml
+                                  # (FABRIC-3, 2026-11-11)
 
 jobs:
   image: