Dependency-ordered task runner

Write runner.py with async def run(tasks: dict[str, Task], *, concurrency: int = 4) -> Report. Task is a dataclass with deps: list[str] and fn: Callable[[], Awaitable[Any]]. Run tasks in dependency order with at most concurrency running at once. If a task raises, mark it failed, mark every transitive dependent skipped, and keep running everything else. Detect cycles before starting and raise CycleError naming the cycle. Detect unknown dependency names and raise KeyError. Report is a dataclass with succeeded, failed (name to exception), skipped (name to the failed ancestor name), and order (start order). Use asyncio only. Type hints throughout. Return only the file in one code block.