Expand or collapse all sidebar folders at once

[n00ki]

Problem

Navigating a deep Folder tree leaves many branches open, and returning to a compact overview requires closing each Folder one at a time. Starting from a collapsed tree likewise requires opening each branch individually when someone wants to scan everything.

Desired behavior

Add one state-aware action to the sidebar header:

• When all visible Folders are collapsed, the action expands every Folder.
• When any visible Folder is expanded, the action collapses every Folder.
• The icon, tooltip, and accessible label describe the action that will run.
• The result uses the existing per-workspace Folder expansion persistence.
• Hide the action when the sidebar has no Folders.

This follows the compact file-explorer controls used by tools such as Obsidian, VS Code, and Zed while preserving Hubble's existing sidebar layout.

[github-actions]

Ready to implement — behavior is clear and the current sidebar code already has the pieces this needs.

• Folder expansion state, per-workspace persistence, and toggling all live in one place: packages/ui/src/components/useSidebarTree.ts (localStorage key hubble-sidebar-expanded-folders:<storageScope>, with expandFolder/collapseFolder/toggleFolder already exported). A state-aware expandAll/collapseAll pair plus derived "any folder expanded" / "has folders" flags fit that hook directly.
• The full folder set (including nested and path-compacted chains like deeply/nested/folder) is already derivable from buildFileTree, so expand-all can add every folder id without new data plumbing.
• The sidebar header already hosts state-aware icon actions with matching aria-label/title conventions (new file, new folder, sort toggle) in packages/ui/src/components/Sidebar.tsx (~1277-1341), so the new action follows an existing pattern and layout.
• Hiding the action when there are no folders is a simple check against the built tree.
• The existing auto-expand-of-ancestors effect only fires once per newly highlighted file, so collapse-all will not be immediately undone by it.
• Test coverage exists to extend: packages/ui/src/components/useSidebarTree.test.ts.

One implementation note, not a blocker: the sidebar component is shared, so the control appears in both the desktop app (apps/desktop/src/components/Sidebar.tsx) and web (apps/www/src/shell/Sidebar.tsx). Keep it consistent in both rather than desktop-only.

No duplicate found: no other open or closed issue tracks expand/collapse-all for sidebar folders.

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Triaged by a Warp Factory agent.

[Prajwal-2206]

Hey! I'd like to work on this. Could you assign it to me?

[n00ki]

@Prajwal-2206 Hey 👋 i already issued a PR for this one: #271