• Merge pull request #275 from kaitranntt/kai/feat/antigravity-failover
• docs(agy): add quota management and failover documentation
• fix(agy): edge case handling for quota failover
• Merge remote-tracking branch 'origin/dev' into kai/feat/antigravity-failover
• feat(agy): add preflight quota check with auto-switch
• feat(cliproxy): add doctor subcommand for quota diagnostics
• feat(quota): add fetchAllProviderQuotas and findAvailableAccount