Implement Phase 9: client libraries (Go, Rust, Lisp, Python)

- clients/README.md: canonical API surface and error type reference
- clients/testdata/: shared JSON response fixtures
- clients/go/: mciasgoclient package; net/http + TLS 1.2+; sync.RWMutex
  token state; DisallowUnknownFields on all decoders; 25 tests pass
- clients/rust/: async mcias-client crate; reqwest+rustls (no OpenSSL);
  thiserror MciasError enum; Arc<RwLock> token state; 22+1 tests pass;
  cargo clippy -D warnings clean
- clients/lisp/: ASDF mcias-client; dexador HTTP, yason JSON; mcias-error
  condition hierarchy; Hunchentoot mock-dispatcher; 37 fiveam checks pass
  on SBCL 2.6.1; yason boolean normalisation in validate-token
- clients/python/: mcias_client package (Python 3.11+); httpx sync;
  py.typed; dataclasses; 32 pytest tests; mypy --strict + ruff clean
- test/mock/mockserver.go: in-memory mock server for Go client tests
- ARCHITECTURE.md §19: updated per-language notes to match implementation
- PROGRESS.md: Phase 9 marked complete
- .gitignore: exclude clients/rust/target/, python .venv, .pytest_cache,
  .fasl files
Security: token never logged or exposed in error messages in any library;
TLS enforced in all four languages; token stored under lock/mutex/RwLock

clients/rust/target/debug/.fingerprint/tower-29726767261e568c/lib-tower.json

@@ -0,0 +1 @@
+{"rustc":16243257175721966122,"features":"[\"futures-core\", \"futures-util\", \"pin-project-lite\", \"retry\", \"sync_wrapper\", \"timeout\", \"tokio\", \"util\"]","declared_features":"[\"balance\", \"buffer\", \"discover\", \"filter\", \"full\", \"futures-core\", \"futures-util\", \"hdrhistogram\", \"hedge\", \"indexmap\", \"limit\", \"load\", \"load-shed\", \"log\", \"make\", \"pin-project-lite\", \"ready-cache\", \"reconnect\", \"retry\", \"slab\", \"spawn-ready\", \"steer\", \"sync_wrapper\", \"timeout\", \"tokio\", \"tokio-stream\", \"tokio-util\", \"tracing\", \"util\"]","target":12249542225364378818,"profile":5347358027863023418,"path":6727510142301429929,"deps":[[302948626015856208,"futures_core",false,16395551869408918501],[784494742817713399,"tower_service",false,12829417956076871532],[2251399859588827949,"pin_project_lite",false,15221541811940566033],[2517136641825875337,"sync_wrapper",false,5320438073667373139],[5898568623609459682,"futures_util",false,17637614804480441737],[7712452662827335977,"tower_layer",false,4910726438236040360],[13298363700532491723,"tokio",false,634726864496810915]],"local":[{"CheckDepInfo":{"dep_info":"debug/.fingerprint/tower-29726767261e568c/dep-lib-tower","checksum":false}}],"rustflags":[],"config":2069994364910194474,"compile_kind":0}