docs: recommend downloading Dafny release for DLLs

docs: rewrite README with complete installation and usage guide

fix: handle top-level datatypes and codatatypes without members

feat: include generic type parameters and named returns in signatures

fix: include parameters in module/class header signatures

feat: include imports and exports in module headers

docs: add Dafny search skill for LLM agents

fix: extract fully qualified module names from source

fix: filter included files and bounds-check source extraction

docs: add README with v1 vs v2 comparison and setup guide

fix: abstract/refines modules, const fields, and member safety

Initial v2: Dafny chunker using official DafnyCore parser via pythonnet