feat(web): CI screenshot capture for the mgmt console

Marketing/store screenshots of the console, captured from the built Storybook
with headless Chromium (web/tools/screenshots.mjs) — every Pages/* + Shell/*
story rendered at 1440x900@2x. The page stories render from fixtures, so no live
mgmt API, login, or GPU is needed (the web analogue of apple.yml's screenshots
job). Gated to stable release tags in a standalone best-effort workflow; PNGs
upload as a 30-day artifact, not committed.

- Add Stats + Pairing stories (the two pages that lacked them) with stats/pairing
  fixtures typed against the generated models.
- Extract a pure PairingView (index.tsx -> view.tsx), matching the
  Dashboard/Clients/Stats split, so the page renders host-free from mock state
  instead of racing its polling queries. Container wiring is behaviour-identical.
- Playwright driver + a chromium-capable tag-gated job.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/.gitignore

@@ -4,6 +4,7 @@ node_modules
 .nitro
 dist
 storybook-static
+screenshots
 *.local
 
 # Generated, not committed — regenerated by codegen (see package.json scripts):