chore: bump version to 0.2.1 (#75)

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: sonesuke

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "google-patent-cli"
-version = "0.2.0"
+version = "0.2.1"
 edition = "2024"
 rust-version = "1.93"