Python conventions

Run uv run lint before finishing any change to Python code (--fix applies ruff's fixes and formatting first). It runs ruff lint, ruff format check, mypy and pytest, and also as a pre-commit hook (uv run pre-commit install); never bypass the hook with --no-verify.

• Strict typing. mypy runs strict with disallow_any_explicit. Annotate every function and every variable whose type isn't inferred. Never write Any, cast() or # type: ignore; fix the types.
• Model structured data with types, not dicts: @dataclass(frozen=True) for records built in code, NamedTuple for small immutable tuples, TypedDict for dict-shaped data that must stay a dict, and pydantic models for data from outside the program (JSON, protocol messages, files) that needs validating at run time (the QMP models in vm.py).
• CLIs use Typer: each tool defines app = typer.Typer(...) with typed commands (Annotated[..., typer.Option(...)]).
• Binary parsing: prefer int.from_bytes over struct.unpack_from (untyped tuples). struct.pack_into is fine for writing.
• Use pathlib, not os.path. # fmt: off/on only around data tables formatting would ruin.
• Don't reinvent wheels. Check PyPI first for a maintained library with wheels for our Python (and types, or add a narrow mypy override as for fontTools). Current choices: pycdlib (ISO 9660), fontTools, Pillow, python-dotenv, qemu.qmp, Typer, pydantic, Unicorn. Where none exists, prefer a standard host tool routed through host.py (mtools for FAT floppies). Hand-write only when neither exists, and say why in the docstring (e.g. the DCL decompressor in unpack_isz.py).
• Ghidra classes can only be imported after pyghidra.start(): import them inside functions (# noqa: PLC0415) and under TYPE_CHECKING for annotations. The stubs don't model Java's nulls: annotate variables that can be null as X | None.
• Tests live in tests/ (pytest) for anything checkable without the bring-your-own files: parsers, demangling, formats. Anything needing the ISOs or toolchain is verified by running the tools.
• Dependencies: uv add for runtime, uv add --dev for dev tools.