fix: scope CI concurrency groups to prevent cross-branch cancellation

Storybook runs are now grouped by workflow+ref so PR and main runs
don't interfere. Deploy workflow uses a shared `pages` group with
cancel-in-progress so rapid main pushes cancel stale deploys but PR
runs (which never trigger the deploy workflow) cannot affect main.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: patcon

.github/workflows/deploy-gh-pages.yml

@@ -6,6 +6,10 @@ on:
       - main
   workflow_dispatch:
 
+concurrency:
+  group: pages
+  cancel-in-progress: true
+
 jobs:
   build:
     runs-on: ubuntu-latest

.github/workflows/storybook.yaml

@@ -2,6 +2,10 @@ name: "Storybook"
 
 on: push
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   chromatic:
     name: Run Chromatic

CHANGELOG.md

@@ -27,3 +27,5 @@
 - Renamed `analyzePaintedClusters` → `analyzeLabeledGroups` in the package (neutral terminology; the app adapter preserves backward compat internally).
 
 ### Fixed
+
+- CI workflow concurrency groups: `deploy-gh-pages.yml` now uses `group: pages` with `cancel-in-progress: true` so rapid main-branch pushes cancel stale deploys without being affected by PR branch runs (which never trigger this workflow). `storybook.yaml` now uses `group: ${{ github.workflow }}-${{ github.ref }}` with `cancel-in-progress: true` so PR and main branch Chromatic runs are fully isolated from each other.