Synced from monorepo

Synced from monorepo

Changes:
- Workspace task snapshots only list incomplete backgrounded tasks
- Quiet auth, LSP, and config warnings in the shell
- Fix observability attributes for warm store errors, restore setup, remote tools, and preview denials
- Fail closed when soak metrics are missing
- Run plan-mode exit last in mixed tool batches
- Allow /loop to store prompts that can terminate the loop
- Make subagent maximum nesting depth configurable
- Security: apply sandbox profile to the leader process that executes tools

Source-Revision: 1adcd1f477870e4a97bacbd6be78c8a3bfbac46d