Improving Fable 5's biology safeguards

The update targets the biology safeguards in Claude Fable 5, which previously caused the system to switch to a less capable model after certain biology-related queries. By reducing false positives by about 85%, Fable 5 can now handle a wider range of biology tasks without falling back. This change improves user experience by minimizing interruptions and expanding the model's usable scope in biology. The update reflects ongoing refinement of safety systems to balance caution with capability, and users should see notably fewer fallbacks in everyday biology queries.