Agents Window development

Use this skill for implementation, review, or design work under src/vs/sessions/**.

1. Apply the core principles

• Preserve the layer direction: vs/sessions may import vs/workbench and lower layers; vs/workbench must never import vs/sessions.
• Keep shared Sessions code provider-neutral. Non-provider contributions must not import provider implementations.
• Model mutable session and chat state with observables. Use events for notifications, not as a parallel state model or for control flow.
• Register Sessions menu IDs in browser/menus.ts and consume Menus.*.
• Import contributions from the appropriate sessions.*.main.ts entry point.
• Prefer Sessions-owned adaptations over shared workbench changes unless the capability is genuinely shared.
• Put stable architecture in the owning specification and concrete behavior in tests. Do not preserve implementation chronology as development guidance.