Release v0.59.0-nightly.20260826.g64b5b79a6

What's Changed

• Changelog for v0.58.0-preview.0 by @gemini-cli-robot in #29082
• chore(release): bump version to 0.59.0-nightly.20260825.g812f7a2bc by @gemini-cli-robot in #29083

Full Changelog: v0.56.0-nightly.20260825.g812f7a2bc...v0.59.0-nightly.20260826.g64b5b79a6