Function collect 

pub fn collect(project_root: &Path, phase: PhaseId) -> ShipEvidence

Collect DevFlow’s own structural record of whether phase has shipped.

Nothing in this module writes, commits, checks out, or emits — it is strictly read-only. Every field degrades to its safest value rather than failing: a root with no .devflow directory at all still returns a valid ShipEvidence with shipped: false and state_present: false, never a panic.