feat(testapp): add COOP simulation toggle

[fan-zhang-sv]

Summary

• Add a Simulate COOP toggle to the eth_requestAccounts card in the testapp.
• Register a static service worker that injects Cross-Origin-Opener-Policy: same-origin for ?coop=same-origin navigations, so the simulation works on GitHub Pages.
• Keep the change scoped to the playground by adding a children slot to RpcMethodCard for the toggle UI.

Test plan

• yarn biome lint examples/testapp/src/pages/index.page.tsx examples/testapp/src/components/RpcMethods/RpcMethodCard.tsx examples/testapp/src/components/RpcMethods/shortcut/connectionMethodShortcuts.ts examples/testapp/public/coop-service-worker.js
• yarn workspace sdk-playground typecheck
• yarn workspace sdk-playground build (passes with existing unrelated export warnings for prolink/spend-permission imports)

Made with Cursor

[cb-heimdall]

✅ Heimdall Review Status

Requirement	Status	More Info
Reviews	✅ 2/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1

[github-actions]

Review Summary

PR title: feat(testapp): add COOP simulation toggle — valid Conventional Commits format, no changes needed.

Scope: All changes are confined to examples/testapp (playground app, not published). No SDK or library code is affected.

Assessment: Clean, well-scoped change. No issues found.

Details reviewed:

• Service worker (coop-service-worker.js): Correctly intercepts only same-origin navigation requests with the ?coop=same-origin query param. Properly strips content-encoding and content-length headers to avoid body/header mismatches when injecting the COOP header. skipWaiting + clients.claim ensures immediate activation.

• RpcMethodCard typing: Previously untyped props (implicit any) now have proper types derived from RpcRequestInput and ShortcutType. The children?: ReactNode slot is a clean extension. The values type narrowing from implicit any to object | readonly unknown[] is a correctness improvement.

• connectionMethodShortcutsMap: Explicit Record<string, ShortcutType[]> annotation enables safe indexed access (returns ShortcutType[] | undefined) for the new connectionMethodShortcutsMap[rpc.method] usage pattern.

• COOP toggle logic: ensureCoopServiceWorkerReady correctly handles edge cases (no SW support, already-controlled page, 1s timeout fallback). window.location.assign forces a full navigation, which is necessary for the service worker to intercept the request and inject the COOP header.