Description

Document the behavior of sub-agents during devcontainer rebuilds and how they affect workspace health status in the devcontainers documentation (likely in /docs/user-guides/workspace-lifecycle.md or the new devcontainer docs being prepared in #21080).

As of PR #21098, sub-agents are now excluded from workspace health calculations. This prevents workspaces from showing as "unhealthy" when a devcontainer rebuilds and its sub-agent temporarily disconnects. Users should understand:

1. What happens during a devcontainer rebuild: The sub-agent temporarily disconnects while the container is being rebuilt
2. Health status behavior: The workspace will remain showing as "healthy" during devcontainer rebuilds because sub-agents don't affect workspace health
3. Why this matters: Previously, devcontainer rebuilds would cause the entire workspace to appear unhealthy, which was confusing to users

This should be documented in context with other devcontainer lifecycle information so users understand what to expect when rebuilding their devcontainers.

Impact

Users need to understand workspace health behavior when using devcontainers to avoid confusion during rebuilds. Without documentation:

• Users may be uncertain whether their workspace is actually healthy during a devcontainer rebuild
• Support questions may arise about why health status behaves differently with devcontainers
• Users may not understand the relationship between sub-agents and workspace health

Links

• PR that changed behavior: fix(coderd): exclude sub-agents from workspace health calculation #21098
• Related devcontainer docs rewrite (in progress): docs: rewrite dev containers documentation for GA #21080
• Thread where this request originated: https://codercom.slack.com/archives/D0A1DVC2B8S/p1764888926119129