Auto mode uses 3.5 Flash; MCP tool discovery atomic

What's Changed

• chore(release): bump version to 0.47.0-nightly.20260602.gcfcecebe8 by @gemini-cli-robot in https://github.com/google-gemini/gemini-cli/pull/27644
• Changelog for v0.46.0-preview.0 by @gemini-cli-robot in https://github.com/google-gemini/gemini-cli/pull/27641
• Respect backend definitions for 3.5 flash and Update auto mode to use 3.5 flash when the flag is enabled. by @DavidAPierce in https://github.com/google-gemini/gemini-cli/pull/27645
• fix(policy): add EBUSY fallback and TOML parse recovery (#19919) by @krishdef7 in https://github.com/google-gemini/gemini-cli/pull/21541
• Changelog for v0.45.0 by @gemini-cli-robot in https://github.com/google-gemini/gemini-cli/pull/27642
• update the max amount of times the Antigravity transition banner can be displayed. by @DavidAPierce in https://github.com/google-gemini/gemini-cli/pull/27676
• chore: remove experimental text from browser agent docs by @gsquared94 in https://github.com/google-gemini/gemini-cli/pull/27746
• fix(core): implement atomic update in MCP tool discovery by @luisfelipe-alt in https://github.com/google-gemini/gemini-cli/pull/27619
• Vertex ai model mapping fix by @DavidAPierce in https://github.com/google-gemini/gemini-cli/pull/27749
• Add documentation and migration commands for Antigravity CLI by @DavidAPierce in https://github.com/google-gemini/gemini-cli/pull/27765
• Avoid persisting empty resume sessions by @SandyTao520 in https://github.com/google-gemini/gemini-cli/pull/27770

Full Changelog: https://github.com/google-gemini/gemini-cli/compare/v0.46.0...v0.47.0