Release v0.34.3

What's Changed

• feat(memfs): add read-only file policy [LET-13616] by @letta-integration[bot] in #4910
• fix(context): name the shell in the environment block on macOS and Linux by @cpacker in #4916
• feat(subagents): let subagents launch one nested layer and message their parent [LET-13640] by @cpacker in #4915
• feat(subagents): inherit parent MCP servers automatically by @letta-integration[bot] in #4921
• refactor(subagents): reuse parent linkage for MCP inheritance by @letta-integration[bot] in #4923
• fix(listener): run scheduled turns without a subscribed client by @cpacker in #4925
• docs(tools): point PR creation at WatchPR for readiness by @cpacker in #4922
• fix(agent): finish remote child wait when its Super Run is complete [LET-13200] by @cpacker in #4924
• fix(subagents): TaskStop cancels the remote run before reporting stopped [LET-13347] by @cpacker in #4929
• ci(review): flag system prompt edits in Slack via Amelia [LET-13670] by @cpacker in #4928
• test(tools): keep the shell-secrets background notice out of later test files by @letta-integration[bot] in #4947
• fix(local-backend): retry ChatGPT model-access check failures by @cpacker in #4946
• fix(local): lock OAuth credential refreshes across processes by @cpacker in #4942
• fix(memory): stop gating tools on refreshes of existing checkouts by @cpacker in #4934
• fix(subagents): inherit parent secrets across the MCP trust boundary by @cpacker in #4933
• fix(tools): restore the foreground sleep block in Bash by @cpacker in #4932
• fix(tools): reject truncated or agent IDs as SendAgentMessage conversation_id by @cpacker in #4931
• fix(mods): name the cancelling mod in turn_start cancel notices [LET-12868] by @cpacker in #4949
• feat(cli): merge model_settings via letta model set by @cpacker in #4950
• fix(subagents): run external coding-agent CLIs in the workload slice by @cpacker in #4951
• chore: bump version to 0.34.3 by @github-actions[bot] in #4919

Full Changelog: v0.34.2...v0.34.3