Any `<$...>` run in a chat message was treated as an inline skill mention and removed before the request reached the model, so text like `<$(=MonthStart($(vMaxMonthEndINC)))"}, [Registration day] >` silently vanished mid-message and the model only saw the part before it.
The mention regexes accepted any character except `|` and `>` as the skill id, so they matched far more than real mentions. Skill ids are already validated as `[a-z0-9_-]+` when a skill is created, so both regexes now require that charset. Ordinary text passes through untouched while `<$id>`, `<$id|Label>` and `</id|Label>` still resolve and strip as before.
Verified against the reported message (now preserved verbatim) and the three mention forms.
Co-authored-by: Claude <noreply@anthropic.com>
