Release v0.34.4

What's Changed

• fix(sandbox): let memory subagents write their scratchpad by @cpacker in #4952
• revert: remove automatic reply relay from core channels (#4043) by @cpacker in #4956
• docs(channels): keep niche channel behaviors out of the core gateway by @cpacker in #4954
• ci(review): have Amelia flag oversized or scope-creeping PRs by @cpacker in #4955
• chore: bump version to 0.34.4 by @github-actions[bot] in #4957

Full Changelog: v0.34.3...v0.34.4