chore(packaging): MIT license + consolidate metadata into pyproject

- Add MIT LICENSE (PEP 639 'license = "MIT"' + license-files).
- Move all metadata into a [project] table (description, readme, authors,
  keywords, classifiers); drop the now-redundant setup.py.
- Declare bitarray and pycryptodome: used by pm3py.sim and the transponder
  crypto paths but previously undeclared, so a clean install failed on the
  README's own 'from pm3py.sim import SimSession'.
- gitignore build/ and dist/.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

pyproject.toml

@@ -1,6 +1,50 @@
 [build-system]
-requires = ["setuptools"]
+requires = ["setuptools>=77.0.0"]
 build-backend = "setuptools.build_meta"
 
+[project]
+name = "pm3py"
+version = "0.1.0"
+description = "Pure-Python async client for the Proxmark3 NG wire protocol over USB serial."
+readme = "README.md"
+requires-python = ">=3.10"
+license = "MIT"
+license-files = ["LICENSE"]
+authors = [{ name = "Dangerous Things", email = "ops@dangerousthings.com" }]
+keywords = [
+    "proxmark3",
+    "rfid",
+    "nfc",
+    "iso14443",
+    "iso15693",
+    "mifare",
+    "ntag",
+    "t55xx",
+    "smartcard",
+]
+classifiers = [
+    "Development Status :: 3 - Alpha",
+    "Intended Audience :: Developers",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
+    "Topic :: Security",
+    "Topic :: Software Development :: Libraries :: Python Modules",
+]
+dependencies = [
+    "pyserial-asyncio>=0.6",
+    "bitarray>=2.0",
+    "pycryptodome>=3.10",
+]
+
+[project.optional-dependencies]
+dev = ["pytest"]
+
+[tool.setuptools.packages.find]
+include = ["pm3py*"]
+
 [tool.pytest.ini_options]
 testpaths = ["tests"]