Wire server.py handlers to the auth helper: forfeit requires validator
service token or admin session (client API keys rejected); billing summary/
settlements/registry-wallets and benchmark endpoints require admin/service;
the three gossip mutation endpoints require a fresh hive HMAC signature and
outgoing gossip pushes are signed. Dashboard sends its session token on
panel fetches. Existing tests updated for the new gates.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
