test: fix Codex contract refresh fallback

[jalehman]

What

Fixes the OpenAI Codex provider runtime contract so the refresh-fallback assertion uses the current runtime mock path and avoids the bundled loader's Jiti mock bypass for that one case.

Why

This is a Forge follow-up for an unrelated test failure discovered while preparing PR #54392.

Changes

• Update the stale Codex runtime mock path
• Instantiate Codex provider directly for fallback contract

Testing

• pnpm test -- src/plugins/contracts/runtime.contract.test.ts -t "owns refresh fallback for accountId extraction failures"
• pnpm test -- src/plugins/contracts/registry.contract.test.ts

[greptile-apps]

Greptile Summary

This test-only PR fixes two issues in runtime.contract.test.ts that caused the openai-codex refresh-fallback assertion to fail:\n\n1. Stale mock path corrected: vi.mock(\"../../../extensions/openai/src/openai-codex-provider.runtime.js\", ...) referenced a non-existent src/ subdirectory; the path is updated to ../../../extensions/openai/openai-codex-provider.runtime.js, which correctly matches the actual source file at extensions/openai/openai-codex-provider.runtime.ts.\n2. Direct instantiation to avoid Jiti mock bypass: The test now calls buildOpenAICodexProviderPlugin() directly instead of going through requireProviderContractProvider(\"openai-codex\") (the bundled contract loader). This ensures Vitest's module mock for the runtime wrapper is in effect when refreshOAuth triggers the dynamic import of ./openai-codex-provider.runtime.js, rather than being bypassed by Jiti's loader.\n\nBoth changes are correct and well-scoped, with a clear comment explaining the Jiti bypass rationale.

Confidence Score: 5/5

This PR is safe to merge — it is a test-only fix with no production code changes.

The diff touches a single test file, corrects a stale mock path to match the real file location, and switches one provider instantiation to bypass a known Jiti loader limitation. Both changes are technically correct and narrowly scoped. No logic, APIs, or production behavior is affected.

No files require special attention.

Important Files Changed

Filename	Overview
src/plugins/contracts/runtime.contract.test.ts	Fixes stale Codex runtime mock path and switches fallback test to direct provider instantiation to avoid Jiti mock bypass.

_{Reviews (1): Last reviewed commit: "test: fix codex contract refresh fallbac..." | Re-trigger Greptile}