Rename all crate directories, package names, binary names, proto
package/module paths, ALPN strings, env var prefixes, config filenames,
mDNS service names, and plugin ABI symbols from quicproquo/qpq to
quicprochat/qpc.
Implements quicproquo-py with two transport backends:
- Async QUIC transport via aioquic with v2 protobuf wire format
- Synchronous Rust FFI transport via CFFI wrapping libquicproquo_ffi
Includes manual protobuf encode/decode (no codegen), full RPC coverage
(auth, delivery, channels, users, keys, health), PyPI-ready packaging,
async echo bot and FFI demo examples, and 15 passing unit tests.
