Introduces a new Makefile target 'docker-chain-node' to build the lthn/chain Docker image. Updates the lthn-chain Dockerfile with improved comments, sets BUILD_TESTNET=1 by default, and clarifies multi-stage build targets. Also updates the docs submodule reference.
Added BUILD_TYPE variable to allow specifying build type (e.g., Release, Debug) for all build targets. Updated Conan and CMake commands to use the configurable build type. Cleaned up apple-clang profile files by removing unnecessary user_presets configuration.
Introduces a TESTNET variable to the Makefile and passes it from GitHub Actions workflows based on the chain-network input. Updates CMake build commands to include the TESTNET flag, improves help output formatting, and comments out unused genesis targets for clarity.
Renamed and reorganized CMake build profiles for consistency, removing unused Android, iOS, and MinGW profiles. Updated GitHub Actions workflows and Makefile to use new profile names and increased build parallelism for faster builds.
