`Gemini AI Pro` shifts to compute-based usage limits

The old 1,000 AI credits/month base perk is being removed. Usage now depends on prompt complexity, features, and chat length, so heavy Antigravity or Flow sessions need closer cost checks.

• —Gemini app limits now refresh every 5 hours until the weekly cap is reached; Pro gets 4x the non-subscriber limit.
• —The limit model counts compute, not just product buckets: longer chats, harder prompts, and feature choice directly affect quota burn.
• —Flow and Antigravity are first in line for product-based limits plus paid AI credits. Agent-heavy workflows can hit paid top-ups faster.
• —Removing the included 1,000 AI credits changes the subscription math. Track real session usage before treating Pro as a fixed-cost tool.