- Replace setup.py with pyproject.toml (setuptools-scm, PEP 621)
- Replace README.rst with comprehensive README.md
- Add Makefile for build/test/lint/develop workflow
- Add full integration tests (test_full.py) covering gate selection
  counts, synthesis, and reversible circuit synthesis
- Add test data: bitonic_sorting_network_4.circ, full_adder_subtractor.circ,
  cmp.cl, reversible.cl
- Move UnknownComponent exception to circuit/parser_error.py
- Fix component library find() to return None instead of raising on
  unknown types (let caller decide)
- Make circuit parser's make_component public and add docstring
- Fix std_micro.cl: replace xor with and (matches minimal gate set)