Code Review: fix(test): codetool test timeout

Overview

This PR replaces dynamic await import('../index') calls within each test case with a single static import { generateToolEnvironment } from '../index' at the top of the file. This resolves a test timeout issue (10s → 4ms) and eliminates an import-order lint warning.

What's Good

• Root cause is correct: Dynamic imports inside test cases cause Vitest to re-evaluate the module (and all its transitive dependencies) on every invocation, which explains the timeout. A static import lets Vitest resolve the module once and cache it.
• Mock setup remains valid: All vi.mock() calls are still hoisted above the static import by Vitest's transform, so mock isolation is preserved.
• Tests become synchronous: Removing async/await from test cases that don't need it is a clean improvement — it simplifies the test signatures and makes failures easier to diagnose.
• CI passes: All checks (basic-checks, general-test, render-test) are green.
• Minimal diff: +11 / -17 lines — focused and easy to review.

Minor Observations

1. Comment wording change (line 5): the original "which is the default export" reads slightly better grammatically than "which is default export", but this is purely cosmetic and not worth blocking.

Risk Assessment

• Low risk — this is a test-only change with no impact on production code.
• The mock hoisting behavior in Vitest is well-documented and reliable for static imports, so this pattern is safe.

Verdict

Clean, focused fix that correctly addresses the root cause. LGTM.