Add two new sections to the Pallas documentation:
- Sampling parameters: explain that temperature/top_p/top_k are
configured via the fast-agent decorator's `request_params`, with a
provider support matrix and a note on Claude Opus 4.7 stripping these
params in favor of `output_config.effort`.
- Metrics: document the Prometheus `/metrics` endpoint exposed on the
registry port, including scrape config, full metrics reference table,
and notes on where each metric is captured.
Robert Helewka
ca7d714a31