Cap the model-visible skills section to a small share of the context
window, with a fallback character budget, and keep only as many implicit
skills as fit within that budget.
Emit a non-fatal warning when enabled skills are omitted, and add a new
app-server warning notification
Record thread-start skill metrics for total enabled skills, kept skills,
and whether truncation happened
---------
Co-authored-by: Matthew Zeng <mzeng@openai.com>
Co-authored-by: Codex <noreply@openai.com>
