fix(wgsl): resolve tmpdir symlink before comparing webpack fileDependencies on macOS

[ColinL-code]

Diagnosis

The "addDependency wiring" test in webpack-real.test.ts asserts that stats.compilation.fileDependencies contains the transitively-imported helper.wgsl. On macOS this assertion fails, even though the loader correctly registers the dependency.

This is because os.tmpdir() on macOS returns a path under /var/folders/..., but /var is itself a symlink to /private/var. Webpack's resolver follows symlinks by default, so fileDependencies records the resolved /private/var/folders/.../helper.wgsl path, while the test compares against the un-resolved /var/folders/.../helper.wgsl it wrote the fixture to. So the string comparison fails even though the file is tracked properly.

Fix

Resolve the expected path with fs.realpath before comparing.

Evidence (before / after)

Before (macOS, node v22.22.2):

AssertionError: expected false to be true
 ❯ packages/wgsl/tests/webpack-real.test.ts:78:64

After: all 5 tests in webpack-real.test.ts pass.

Gates run (macOS, Node 22.22.2)

Gate	Result
pnpm typecheck	✅
pnpm test:fast	✅ 766 passed / 76 skipped

Notes

No changeset included since this is a test-only change, no published package behavior affected.

[vercel]

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[matiasngf]

Reviewed the test-only path canonicalization and its security impact. The change correctly resolves macOS /var → /private/var path differences without altering production behavior. Targeted webpack test passes locally (5/5).

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[matiasngf]

@ColinL-code can you please sign your commit?

[ColinL-code]

Signed my commit