Phase 1 of de-duplicating config normalization. isObject/boolOr/clampNum/
clampInt were copied verbatim across notifications/config and webui/
ui-config; give them a single home as @snowluma/common/coerce (new
per-file subpath export, zero deps — fits common's leaf-utility charter).
Byte-identical to both originals (adversarially verified), so the phase-2
migration is a pure delete-and-import. clampInt is clamp-then-trunc;
10 table tests pin types, numeric-string coercion, non-finite→fallback,
bounds, and the clamp/trunc order. Not yet wired into consumers.
DrSmoothl