chore: update project meta and build configuration

docs: rewrite project documentation with accurate architecture and usage

feat(cli): implement MCP connection, tool discovery, and CLI generation

vendor(mcp-go): add MCP Go reference source as submodule

fix(cli): fix flag validation and argument handling

feat(cli): implement basic CLI structure with Admiral

feat(porting): initialize Crystal port of clihub

docs: add agentic engineering meta-structure