* fix(prometheus): sanitize label values to prevent metric scrape failures
Unicode characters like U+2028 (Line Separator) in Prometheus label values
break the text exposition format, causing scrapers (e.g. Datadog) to fail
parsing the entire /metrics endpoint. One bad label value causes ALL metrics
to be lost, not just the affected metric.
Add _sanitize_prometheus_label_value() and apply it in prometheus_label_factory()
and all direct .labels() call sites.
* fix(prometheus): handle non-string label values in sanitization
Coerce non-string values (int, bool, float) to str before applying
sanitization, preventing AttributeError on .replace() calls.
* fix(prometheus): run sanitization on coerced non-string values
Non-string values should be coerced to str and then sanitized (not
returned early), so their string representations also get cleaned.
* fix(prometheus): widen type hint to Optional[Any] for label value sanitization
* feat: add clientip and user agent in metrics
* fix: lint errors
* Add model id and other req labels
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Co-authored-by: Krish Dholakia <krrishdholakia@gmail.com>
