feat: DSL parser, eval system, and project structure
- Hand-written lexer + recursive-descent parser for .kap package definitions
- Package constructs: const, license, provides, outputs, patches, depends
(version-constrained, feature-gated, output-targeted), features (enabled/
forced/flag), config files (default/replace/merge with cfg interpolation),
env (?= soft-set), prepare/build/check/install phases
- Evaluator: recursive resolver for prefix, jobopts, destdir, userargs,
cfg.*, feature.*, package vars
- Comments: // single-line, /* */ multi-line
- /kappa/{bin,temp,db,system,system/builds} path layout
- Clang 22, C++23, CMake + vcpkg (tomlplusplus)
- .clangd + .clang-tidy configured