v0.2.1 — complete API documentation and type exports

Patch Changes

• 6f5e953: Complete the API documentation surface and export the types it references.

  Every exported symbol — including interface and class members — now carries JSDoc, and both entrypoints carry an explicit module doc, so generated documentation (JSR, editors) is complete. Types that public signatures reference are now exported instead of being reachable-but-unnamed: Transaction, Entry, Key, Value, Open, and the lens seam Store from the main entry; Transaction, Entry, Key, Value, and Store from the browser entry. No runtime behavior changes.