@standard-schema/spec resolution fails in pnpm monorepos with Vitest

[schickling]

When using Effect in a pnpm monorepo with Vitest, the re-exported @standard-schema/spec fails to resolve:

Error: Cannot find package '@standard-schema/spec' imported from ...

Root Cause

1. effect has @standard-schema/spec as a direct dependency
2. In pnpm strict mode (default), it's isolated to effect's node_modules/
3. Vite resolves imports from the importer's location, not the exporter's
4. When a consuming package runs vitest, Vite can't find @standard-schema/spec

Node.js ESM works correctly - this is Vite/Vitest-specific.

Reproduction

1. pnpm monorepo (strict mode is default)
2. Package A depends on Package B
3. Package B depends on effect and re-exports or uses StandardSchema
4. Run vitest in Package A → fails

Workaround

Add vitest resolve alias in affected package:

// vitest.config.ts
resolve: {
  alias: {
    '@standard-schema/spec': 'node_modules/effect/node_modules/@standard-schema/spec',
  },
}

Suggestion

Consider making @standard-schema/spec a peer dependency so consumers install it explicitly and pnpm resolves it correctly.

Environment

• pnpm 10.x (strict mode)
• vitest 3.x
• effect 3.x"