Reuses ShellTool._is_dangerous as the default bash filter for PLANNING
and VERIFICATION phases, closing the regex ceiling documented in Wave 3.
- Convert ShellTool._is_dangerous and _is_single_command_dangerous to
@staticmethod (backward-compatible; instance calls still work via
Python's descriptor protocol).
- Widen PhasePolicy.bash_command_filter field type to
dict[PhaseState, Callable[[str], bool] | re.Pattern | None].
- is_bash_command_allowed dispatches on callable vs pattern at call time.
Empty commands short-circuit to allowed (Wave 3 contract; ShellTool
emits the clearer empty-command error).
- to_dict serializes callables as <callable> for log readability.
- default_policy() now wires ShellTool._is_dangerous for PLANNING and
VERIFICATION. _DEFAULT_BASH_FILTER kept for backward compat with
configs that pass a re.Pattern.
- Tests: characterization tests pin Wave 3 behavior (rm/mv/cp/echo >
still blocked) plus new edge-case coverage for ceiling closed
(dd of=/dev/sda, :>file, chain operators, pipe segments).
9e28ab315e