v2.7.2a4

Pre-release for live testing on agentos-railway (agno 2.7.2a4 + agnoctl 0.1.2a4, lockstep).

Over v2.7.2a3:

• Consent-page CSP no longer blocks the OAuth redirect (form-action directive dropped) — fixes the built-in AS sign-in flow in browsers that enforce it
• Picks up main: AG-UI client_tools support (#8565)