[vitest-pool-workers] Install wrapper prototype proxy once

[thinkter]

Fixes #15092.

Summary

Preserve the delayed wrapper-prototype proxy installation required by workerd introspection, while guarding it so each wrapper class installs exactly one proxy. Later constructions now reuse that prototype instead of wrapping the previous proxy and accumulating get traps. The existing trap behavior for inherited, ignored, symbol, and unknown RPC properties is unchanged.

Regression coverage

Added deterministic package-level tests that compare prototype identity before the first construction, after the first construction, and after a later construction. The tests also cover inherited properties, unknown RPC-property delegation, and the ignored self and symbol cases without relying on timing or source-text assertions.

---

• Tests
  • Tests included/updated
  • Automated tests not possible - manual testing has been completed as follows:
  • Additional testing not necessary because:
• Public documentation
  • Cloudflare docs PR(s):
  • Documentation not necessary because: this fixes internal wrapper lifecycle behavior without changing the public API.

Validation:

• pnpm --filter @cloudflare/vitest-pool-workers exec vitest run test/proxy-prototype.test.ts (2 tests passed)
• pnpm --filter @cloudflare/vitest-pool-workers check:type
• pnpm exec oxfmt --check packages/vitest-pool-workers/src/worker/entrypoints.ts packages/vitest-pool-workers/src/worker/proxy-prototype.ts packages/vitest-pool-workers/test/proxy-prototype.test.ts .changeset/lazy-prototype-proxy.md

Note

This is a contribution from an AI agent: OpenAI Codex, GPT-5.6.

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[changeset-bot]

🦋 Changeset detected

Latest commit: 7b9bf1a

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@cloudflare/vitest-pool-workers	Patch

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[workers-devprod]

Codeowners approval required for this PR:

• ✅ @cloudflare/wrangler

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commit: 7b9bf1a

[dario-piotrowicz]

Looks good to me! Thanks for the fix @thinkter 😄

[workers-devprod]

Codeowners reviews satisfied