Keep the legacy sidebar a supported option

[kirillrocks]

The old sidebar is still available today under Settings → General → Legacy features. Please keep it there, with no planned removal.

I gave Sidebar V2 a real chance. I used it every day for a week and did not let myself switch back. It still feels uncomfortable, and I am slower with it than with the old sidebar.

I am not asking to change Sidebar V2. I am asking for the legacy sidebar to stay a supported setting, so people who work better with it can keep using it.

[angelaman]

Same here. For my workflow, losing the legacy sidebar's organization is a deal-breaker.

I work on several tickets in one repository in parallel. Each ticket has its own full clone with its own build, test, and lint setup, so they run side by side without worktree switching or merging back to test. Each ticket usually has several agent threads.

What the legacy sidebar gives me:

• Threads grouped under their project folder, so all threads for one ticket sit together.
• All projects visible. I can leave a low-priority project collapsed and come back to it later.
• Compact rows with just enough information to find what I need.

In the flat sidebar, threads from every ticket mix in one list, sorted by status instead of by work. Rows show more than I need and take much more space, so it's hard to find where anything is.

Alternatives I tried that don't work for me:

• The project filter dropdown: one project at a time, two clicks to switch.
• Pinning: no grouping structure.
• T3-managed worktrees per thread: I need full independent clones with their own tooling.

Smallest ask: keep it working and move it out of "Legacy features" so it's clearly supported.

Related: #6751 (group threads by worktree), #10196 (its author went back to the legacy sidebar for the same reason), #11685 (compact mode added, then removed), #12090 (per-checkout grouping).