Both relay Slack knobs read their value through bool(), while the native
adapter they mirror uses str(raw).strip().lower() in {"1","true","yes","on"}.
A YAML-quoted string diverges:
dm_top_level_threads_as_sessions: "false" → relay True, native False
Non-empty strings are truthy, so the escape hatch is silently ignored in
exactly the shape an operator writes to switch it OFF. reply_in_thread has the
same defect and gates reply placement, session keying and run.py's progress
resolver, so one quoted "false" misfires three ways.
Route both through a shared _coerce_flag mirroring native's predicate. Real
booleans pass through untouched; None falls back to the default. Contract §8
documents the accepted spellings.
Tests: both knobs parametrized over the true/false spellings native accepts,
plus the absent-key default.
Ben Barclay
0dc293f4f7