Release v0.1.1

Changes

Fixed

• The Ubuntu Release CI job no longer fails intermittently with SIGILL. The vcpkg cache is now
  keyed on the runner's CPU feature set, not just the OS. The SlickQuant dependency libraries
  (slick-net, hyperliquid-cpp, …) build their Release config with -march=native, so vcpkg
  produced binaries tuned to whichever runner compiled them; restoring that cache onto a runner with
  a narrower instruction set made the tests die on an AVX-512 opcode (vmovdqu8) inside
  slick::net::Websocket's constructor, reached from HyperliquidRestOrderGateway. That is why a
  re-run sometimes passed — it depended on the CPU the cache came from.
• Release builds on GCC/Clang no longer pass -march=native. It is now behind a new
  ENABLE_NATIVE_ARCH option, off by default. Baking the build machine's instruction set into the
  binary broke two things: the Ubuntu Release CI job started failing with SIGILL in every test
  that exercises the exchange and order-book paths, and — more seriously — ci.yml uploads those
  Release binaries for release.yml to attach to GitHub Releases, so published builds would fault
  on any user CPU older than the runner that produced them. The flag is still available for local
  and self-hosted production builds via -DENABLE_NATIVE_ARCH=ON.
• Exchange::start() no longer dereferences a null md_publisher_. Only CoinbaseExchange and
  HyperliquidExchange construct a publisher, so any other venue key — which falls through to the
  generic Exchange — segfaulted the process on startup. Because nlohmann::json iterates object
  keys in sorted order, the cme block in the committed sample config crashed slick-sim before
  either working venue was even constructed.
• enabled is now honoured for every venue. It is read once in the Exchange base constructor and
  checked by all three start() implementations, which return early with a warning when it is
  false. Previously the check lived only in the coinbase and hyperliquid branches of main.cpp,
  so "enabled": false on any other venue was silently ignored.

Changed

• Sample config (config/slick_sim.json):
  • The cme block is now "enabled": false, uses an mbo_live_feed placeholder feed instead of a
    copied Hyperliquid one, and no longer collides with Hyperliquid's ports — its order gateway
    moves to 4003 and its market data publisher to 5002 (it previously shared Hyperliquid's 5001).
  • Hyperliquid's order gateway port moves from 4003 to 4002.
  • Dropped coins from the Hyperliquid feed entry.

Added

• Documentation site published to GitHub Pages at
  https://slickquant.github.io/slick-sim/ — MkDocs Material for the narrative
  documentation at the root, Doxygen for the C++ API reference at /api.
• Eleven documentation pages under docs/, in two tracks:
  • Internals — architecture and threading model, order lifecycle, matching engine, order book,
    market data, and a guide to adding an exchange.
  • Integration — full configuration reference, plus Coinbase and Hyperliquid client guides
    covering the REST routes, WebSocket channels and message shapes actually implemented.
  • A Known gaps page recording unimplemented and half-wired code paths.
• documentation.yml workflow: builds both halves of the site, deploys to gh-pages on pushes to
  main, uploads a preview artifact for pull requests, and lints Markdown and checks its links.
  It runs Doxygen directly rather than configuring CMake, so it does not need the vcpkg dependency
  chain.
• Doxyfile.in and a CMake docs target for generating the API reference locally
  (cmake --build build --target docs). The target is skipped when Doxygen is not installed.
• .markdownlint.json and .github/markdown-link-check-config.json.