Update app.py

Refuse out-of-scope requests; guardrail precedence; align collaborator chips

Revert to a curated model list; drop the live /v1/models lookup

Make inline code readable: light chip, not Gradio's dark one

Fix collaborator row labels rendering as SMES

Relabel SME row to SMEs

Collaborators: SME / Implementation Team rows; live auto-updating model list

Count visitors in-app (HF exposes no visitor API for Spaces)

AKD - Gap Detection Agent: corpus-grounded research gap synthesis