Sidebar: group every section by project, with an optional Working row in each boring folder

[GuardedAirplane]

Problem

I run agents in several projects at once. At a glance I want to answer, per project: what is running, what came back and needs me, and what I parked.

The boring sidebar (#21039) already answers part of that: its active list is grouped into project folders. Two gaps remain:

• Default sidebar: the inbox list, Working, Snoozed, and Settled are flat. Every card repeats its project name, and with five or six projects running it's hard to tell which project a thread belongs to without reading each card.
• Boring sidebar: Snoozed and Settled stay flat under the folders. Inside a folder, running threads sit mixed in with threads that finished or need you, so a folder doesn't show at a glance what's done and what's still going.

Proposal

My personal preference is to keep threads organized by project, while using the same Done and Working sections as the default sidebar. I want the project organization together with that familiar separation between work that has finished and work that is still running.

The base proposal can stand alone; the second part is an optional extension.

Part 1: Sections by project (base)

A Labs switch, Settings → Labs → Sections by project, off by default.

• Default sidebar: the inbox list, Working, Snoozed, and Settled list threads under plain project labels, in the same project order as the boring sidebar's folders. Cards under a label drop their repeated project name. When Working section is on, a thread leaves its project in the inbox for its project in Working while it runs, and comes back when it finishes.
• Boring sidebar: Snoozed and Settled get the same project labels. Folders are unchanged.
• Keyboard navigation, ⌘1–9 hints, and range select follow the drawn order. With the switch off, both sidebars are unchanged. Mobile is unchanged.

Part 2: a Working row in each boring folder (optional extension)

Only when Boring sidebar and Sections by project are both on: each project folder keeps its running threads under a collapsible Working N row at the bottom of the folder. Finished threads, and threads that need you, sit above it at the top of the folder.

• Working rows start closed; each folder remembers its open state on the device.
• The open thread stays visible even under a closed Working row or a closed folder.
• Every other combination behaves as Part 1 leaves it.

Part 1: default sidebar, Sections by project	Part 2: boring sidebar, per-folder Working rows

How this differs from #30980

#30980 asks to bring back the global Working shelf in the boring sidebar: running threads leave their folders for one cross-project Working section above Snoozed and Settled. That answers "what is running across everything?"

Part 2 does the opposite: running work stays inside its project, so a folder answers "where is this project at?" In that mode there is no global Working shelf. The two aren't mutually exclusive, but they pull the boring sidebar in different directions, so it seems worth a maintainer call on which one (or neither) the boring sidebar should have. Part 1 doesn't depend on that decision.

Tradeoffs

• No manual ordering while it's on. With Sections by project on, rows can be dragged onto the composer to mention a thread, but not reordered within the sidebar, the same as the boring sidebar's folders today. Your saved order returns in the default sidebar when both Sections by project and Working section are off.
• One more Labs switch, and its interaction with the boring sidebar adds a combination to reason about. To avoid two "group by project" names in Labs, the boring switch would be retitled Boring sidebar (project folders).
• Part 2 hides running threads behind a closed row by default. The folder's count and status dot still cover them.

Implementations for evaluation

• feat(web): sidebar sections can list threads by project #32536: Part 1.
• feat(web): boring sidebar folds working threads into each project folder #32565: Part 2, stacked on feat(web): sidebar sections can list threads by project #32536.

Both were opened without prior approval. They're here so you can see the behavior, not as a request to merge them as-is.

Decision requested

1. Is Part 1 (project labels in the sidebar sections, opt-in) a direction you want? If so, as a Labs switch, or something narrower (for example, only the default sidebar, or only Snoozed and Settled)?
2. Separately, should the boring sidebar keep running work inside each folder (Part 2), take the global shelf from Boring sidebar: keep the Working section when grouping by project #30980, or neither?

I'll narrow or close the PRs to match whatever you decide.

Drafted by Claude Opus 5.5 via Claude Code, on behalf of @GuardedAirplane.