Re-enable `@ark/attest` completion snapshots for Issue #796

[yamcodes]

Summary

The type regression tests implemented in #894 currently use Vitest's built-in expectTypeOf for inference checking. Direct completion snapshots (using .completions()) are currently commented out due to a version conflict between @ark/attest@0.56.0 and arktype@2.2.0.

Context

Issue #796 identified a regression where string literal autocompletions for ArkType DSL values were lost. While expectTypeOf verifies that the types evaluate correctly, @ark/attest is the essentially only tool that can directly snapshot the IDE completion suggestions to ensure the developer experience doesn't regress.

Implementation Steps (Follow-up)

Once the upstream conflict is resolved (see arktypeio/arktype#1617):

1. Uncomment tests in packages/arkenv/src/type-regression.test-d.ts:
   • Find the commented-out it("snapshots DSL completions ...") block.
   • Restore the attest calls.
2. Re-enable globalSetup in packages/arkenv/vitest.config.ts:
   • Uncomment globalSetup: ["test/setup-attest.ts"].
3. Update Snapshots:
   • Run pnpm test:types (which should now execute both Vitest typechecks and Attest snapshots).
   • If completions change, update them using vitest run --update-snapshots.

Dependencies

• Blocked by: Upstream ArkType issue regarding @ark/attest compatibility with arktype@2.2.0: [attest] ParseError: "A Scope already named Array already exists" when used with arktype@2.2.0 arktypeio/arktype#1617