pub fn phase_plan_files(project_root: &Path, phase: u32) -> Vec<PathBuf>Expand description
Discover a phase’s declared plan files: .planning/phases/{NN}-*/{NN}-*-PLAN.md,
sorted. Returns an empty vec if the phase directory is missing or
unreadable — never panics, never errors.
Shared by external_verify_commands and
phase_has_blocking_human_checkpoint so PLAN.md discovery lives in
exactly one place; a second, slightly-different implementation would
drift the moment one is updated and the other isn’t.