v0.4.0

Changed

• JSON library: migrated from nlohmann/json v3.11.3 to
  Glaze v7.6.0 via FetchContent
  (commit on feat/glaze-migration, 2026-05-11). Glaze's compile-time
  reflection delivers a ~2-4x parse speedup on representative CLOB
  orderbook payloads (200 levels/side, ~14.6KB) — measured median on
  x86_64-v3 GCC 13.3 -O3 -DNDEBUG: nlohmann ~500 us/op → glaze
  ~290 us/op (Decimal::from_string dominates the per-level work; the
  JSON parse itself is ≈3x faster but fixed-cost relative to the 400
  decimal conversions per parse).
• Affected code: src/clob/websocket.cpp (the CLOB WS inbound
  variant-dispatch parser) and apps/polymarket_us_cli.cpp (the
  stdin/stdout JSON envelope). Both use glz::generic because their
  shapes are dynamic per-message-type / per-command — a static
  glz::meta per type would be heavier on maintenance with no
  measurable speedup, given how few REST response models exist in the
  SDK at this point (CLOB and Gamma client structs are stubs; the
  US REST client returns Result<std::string> and lets callers parse).
• Public SDK API (polymarket::clob::*, polymarket::us::*,
  polymarket::crypto::*) is unchanged. Consumers (polymarket-trader,
  polymarket-data) build without modification.
• New tests: tests/unit/glaze_test.cpp (shape-parity guard with 6
  Catch2 cases including a bool/string overload-set regression) and
  tests/parse_benchmark.cpp (1k-iteration parse benchmark, capped at
  1000 us/op via ctest --timeout). CMakeLists install-list no longer
  re-exports nlohmann_json. Glaze is exposed as a build-interface
  include path (matching how nlohmann was integrated pre-migration)
  to sidestep CMake's "INTERFACE target not in export set" error on
  the installable static libs.