CI: concurrency groups on cultmesh-portability and quic-native

The capacity-1 forge runner is flooded by superseded pushes. Group per
workflow + ref; cancel-in-progress only for pull_request and non-tag push.
Tag pushes (quic-native release) and workflow_dispatch are never cancelled.
publish-packages (tags + dispatch) and cultnet-interop (dispatch only) get
none: every run of theirs is a release or a manual probe.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.github/workflows/cultmesh-portability.yml

@@ -8,6 +8,12 @@ on:
   pull_request:
   workflow_dispatch:
 
+concurrency:
+  # A newer push or PR update replaces the older run on the same ref. Tag pushes and
+  # workflow_dispatch runs are never cancelled: a tag run carries a release.
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' || (github.event_name == 'push' && !startsWith(github.ref, 'refs/tags/')) }}
+
 jobs:
   reactive-and-resource-lifetime:
     name: ${{ matrix.os }} reactive semantics and leases

.github/workflows/quic-native.yml

@@ -18,6 +18,12 @@ on:
   pull_request:
   workflow_dispatch:
 
+concurrency:
+  # A newer push or PR update replaces the older run on the same ref. Tag pushes and
+  # workflow_dispatch runs are never cancelled: a tag run carries a release.
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' || (github.event_name == 'push' && !startsWith(github.ref, 'refs/tags/')) }}
+
 permissions:
   contents: read