v0.13.0

Added

• ClaudeCode.Test module - Req.Test-style test helpers for mocking Claude responses ([9f78103])
  • stub/2 - Register function or static message stubs for test isolation
  • allow/3 - Share stubs with spawned processes for async tests
  • set_mode_to_shared/0 - Enable shared mode for integration tests
  • Message helpers: text/2, tool_use/3, tool_result/2, thinking/2, result/2, system/1
  • Auto-generates system/result messages, links tool IDs, unifies session IDs
  • Uses NimbleOwnership for process-based isolation with async: true support
• ClaudeCode.Test.Factory module - Test data generation for all message and content types ([54dcfd7])
  • Struct factories: assistant_message/1, user_message/1, result_message/1, system_message/1
  • Content block factories: text_block/1, tool_use_block/1, tool_result_block/1, thinking_block/1
  • Stream event factories for partial message testing
  • Convenience functions with positional arguments for common cases
• Testing guide - Comprehensive documentation for testing ClaudeCode integrations ([7dfe509])