Port codebase to build with OpenSSL 3.x and Boost 1.90+:
- Rewrite bignum.h to use BIGNUM* pointer instead of inheriting from opaque BIGNUM
- Fix ECDSA_SIG, EVP_CIPHER_CTX, HMAC_CTX opaque type access across key.cpp, crypter.cpp, smessage.cpp
- Modernize Boost.Asio API (io_context, resolver, executor) in trianglesrpc.cpp
- Remove embedded Tor v2 client (incompatible with OpenSSL 3.x), keep Tor v3 SOCKS5 approach
- Update header logo to Cryptographic Triangles branding (300x63)
- Replace Bittrex exchange link with Pinball (313.cash) across all locales
- Fix MSYS2/MinGW64 build: linker flags, Boost library names, miniupnpc static linking
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>