Release v0.28.18

What's Changed

• feat(cli): review historical coding-agent sessions via @letta-ai/trajectory by @sarahwooders in #3459
• fix(tools): clamp total tool return size before it reaches the model by @cpacker in #3470
• fix(tools): scrub secrets from overflow file content by @cpacker in #3471
• feat: centralize reflection transcript normalization by @devanshrj in #3467
• feat(cli): surface OpenRouter reasoning efforts by @AriWebb in #3469
• chore: bump version to 0.28.18 by @github-actions[bot] in #3475

Full Changelog: v0.28.17...v0.28.18