Letta Code 0.28.11 አውርድ

What's Changed
- fix(slack): stop download-file from wedging turns on slow or stalled transfers by @cpacker in https://github.com/letta-ai/letta-code/pull/3382
- fix(models): disable Kimi K3 reasoning controls by @just-cameron in https://github.com/letta-ai/letta-code/pull/3387
- fix(subagents): stop losing subagent results to silent stdout truncation by @abhay-codes07 in https://github.com/letta-ai/letta-code/pull/3303
- fix: correct GPT-5.6 context windows and add explicit 1M variants by @cpacker in https://github.com/letta-ai/letta-code/pull/3383
- fix: never omit context_window_limit on model-bearing updates [LET-9786] by @cpacker in https://github.com/letta-ai/letta-code/pull/3386
- chore: bump version to 0.28.11 by @github-actions[bot] in https://github.com/letta-ai/letta-code/pull/3388
Full Changelog: https://github.com/letta-ai/letta-code/compare/v0.28.10...v0.28.11