v0.6.6 - Concurrent Cancellation Fix

Fixed

• Interrupt example: Replaced the deadlocking Arc<Mutex> concurrent-cancellation pattern with Client::interrupt_handle(), so the receive loop retains exclusive ownership of the client while another task signals cancellation (fixes #7).
• Documentation: Corrected the README concurrent-cancellation example and clarified that interrupted partial manual responses are discarded rather than committed to conversation history.
• Package: Excluded CLAUDE.md and .markdownlint.json development files from published crate archives, preventing a recurrence of the packaging issue that caused v0.6.3 to be yanked.

Testing

• Added regression coverage for non-locking concurrent cancellation and development-file package exclusions.
• Passed RustSec, rustfmt, clippy, all tests and doctests, warning-denied docs, Rust 1.85, package verification, and the full GitHub CI matrix.

Crates.io package