Release v0.27.2

What's Changed

• feat(listener): add typed Letta Code upgrade command by @kianjones9 in #2599
• fix(telemetry): add agent step/duration to reflection telemetry and send to user feedback by @amysguan in #2617
• refactor(extensions): consolidate event emission capability by @carenthomas in #2688
• refactor(extensions): pass backend directly through adapter by @carenthomas in #2689
• refactor(extensions): share conversation handle with tools by @carenthomas in #2691
• refactor(extensions): extract disabled adapter by @carenthomas in #2692
• test(extensions): split disabled adapter coverage by @carenthomas in #2694
• refactor(extensions): simplify adapter options type by @carenthomas in #2695
• fix(channels): stabilize Telegram account commands by @shelleypham in #2693
• fix(resume): keep default conversation permanently pinned by @kianjones9 in #2687
• docs: add system prompt release note by @sarahwooders in #2684
• revert: "docs: add system prompt release note" by @cpacker in #2697
• chore: bump version to 0.27.2 by @github-actions[bot] in #2696

Full Changelog: v0.27.1...v0.27.2