pub fn cap_external_string(
field: &'static str,
raw: String,
max_bytes: u16,
) -> StringExpand description
Cap an external string at max_bytes (UTF-8-safe boundary), append
the …<truncated:N> suffix when the input was clipped, and emit
one ObsLabelOversized self-event for telemetry. Returns the
(possibly truncated) string. Spec 95 § 3.10 / P2-AH.
Boundary callers (HTTP middleware, bridge field visitor) should
run this on every untrusted string before it lands in
env.labels or the typed payload.