Function probe_tool_input_fresh 

pub fn probe_tool_input_fresh(path: &Path, content_hash_hex: &str) -> bool

The A8-style disk probe behind tool_input_escalation_action: does the file at path currently on disk still hash to content_hash_hex? Unlike probe_read_freshness (which lossy-UTF8-decodes before hashing, to mirror read_file’s own transform), this hashes the RAW bytes directly — write_file writes content.as_bytes() with no transform, so the exact bytes on disk are the fairer comparison. Unreadable/deleted files are never fresh (fails closed, the same direction A8 fails in). A free function (no Reduction/ReductionLog coupling) so it composes with whatever wave-5 escalate() orchestration eventually calls it.