fix(ci): invoke cloudflare:preview via pnpm filter so wrangler resolves

wrangler's bin is hoisted to apps/cloudflare/node_modules/.bin under
pnpm, not repo-root node_modules/.bin, so the previous direct path
failed with ENOENT in CI. Delegating to the package script via
`pnpm --filter` resolves wrangler from the right workspace and keeps
stdout attached (no turbo buffering).

Author: ovflowd

apps/cloudflare/playwright.platform.config.mjs

@@ -11,8 +11,7 @@ export default {
   baseURL: 'http://127.0.0.1:8787',
   webServer: {
     stdout: 'pipe',
-    command:
-      '../../node_modules/.bin/wrangler dev --config ../cloudflare/wrangler.jsonc',
+    command: 'pnpm --filter=@node-core/platform-cloudflare cloudflare:preview',
     url: 'http://127.0.0.1:8787',
     timeout: 60_000 * 3,
   },