Resolve #1612: Add platform runtime edge conformance coverage

[ayden94]

Summary

• Add Express native route handoff coverage for rewrite/rematch behavior and body-size boundary handling.
• Add Node.js platform-package coverage for shutdown listener cleanup and exact raw-body size acceptance.
• Document and assert Cloudflare Workers/Deno conformance coverage parity across English and Korean READMEs, with a patch changeset for affected platform packages.

Verification

• pnpm exec vitest run packages/platform-express/src/adapter.test.ts packages/platform-nodejs/src/index.test.ts packages/platform-cloudflare-workers/src/adapter.test.ts packages/platform-deno/src/adapter.test.ts
• pnpm build
• pnpm typecheck
• pnpm verify:release-readiness

Notes

• pnpm lint still reports pre-existing unrelated Biome issues outside this lane.
• Closes [audit][area:http-runtime] Add platform runtime edge coverage for native routes and limits (P2) #1612