ci(storybook): wire test:storybook into CI (#1251) (#1297)

* ci(storybook): wire test:storybook into CI (#1251)

- Add test:storybook:watch to clients/web for interactive iteration; the
  one-shot script already existed.
- Surface test:storybook at the repo root, delegating to the web client.
- Add a separate CI step that installs the Playwright Chromium binary
  and runs the storybook play-function suite after validate. Kept out of
  validate because the suite needs a real browser and is ~10s slower
  than the unit tests.
- Document the new pre-push step in AGENTS.md.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* ci(storybook): cache Playwright browsers + tighten AGENTS wording

Cache the Chromium binary keyed on clients/web/package-lock.json so the
~150MB download is a no-op on CI cache hits. Also clarify that CI runs
test:storybook after the unit/lint/build checks (not literal `validate`,
which is a local-only script).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/main.yml

@@ -1,6 +1,6 @@
-name: Run install, format, lint, build, and test on every push or pull request
+name: Run install, format, lint, build, and test on every push
 
-on: [push, pull_request]
+on: [push]
 
 jobs:
   build:
@@ -38,3 +38,17 @@ jobs:
       - name: Run tests with coverage
         working-directory: ./clients/web
         run: npm run test:coverage
+
+      - name: Cache Playwright browsers
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-${{ runner.os }}-${{ hashFiles('clients/web/package-lock.json') }}
+
+      - name: Install Playwright browsers
+        working-directory: ./clients/web
+        run: npx playwright install --with-deps chromium
+
+      - name: Run Storybook play-function tests
+        working-directory: ./clients/web
+        run: npm run test:storybook