Let bookmarks be reordered by dragging

[webtools-dotcom]

Bookmarks currently sit in whatever order they were added. Folders exist, but moving a bookmark into one is done through a select dropdown, and there is no way to reorder within a list at all.

There is already a working reference implementation in this repo. src/components/browser/TabBar.tsx does pointer-event based drag reordering for tabs. It is not HTML5 drag-and-drop, it tracks pointerdown/pointermove/pointerup directly, which avoids the drag-image and dragover quirks. Read that first and follow the same approach.

What needs doing

1. Port the pointer-based drag pattern from TabBar.tsx to src/components/sidebar/BookmarksPanel.tsx. The axis is vertical here rather than horizontal.
2. Persist the new order in src/stores/bookmarks.ts. The store is already versioned with a persist migration, follow the existing pattern rather than inventing a new one.
3. Dragging onto a folder should move the bookmark into it, which would be nicer than the current dropdown.

Worth knowing

• Bookmarks are scoped per workspace. Reordering in one workspace must not touch another.
• The panel is inside a scrollable sidebar, so dragging near the top or bottom edge should scroll. TabBar does not have to deal with this, so it is the one part you cannot copy.
• Do not use HTML5 draggable. There was a reason the tab bar avoided it and mixing the two approaches in one app would be inconsistent.

Frontend only, no Rust, no WebView2. Probably the most self-contained issue currently open.

[AeonLogics]

Hello... I loved the idea of a browser for devs in rust I want to help out in this project... Assign it to me and I will make a PR

[webtools-dotcom]

Go for it, no need to wait on an assignment. Open a PR whenever you have something.

One thing that will save you time: src/components/browser/TabBar.tsx already does pointer-based drag reordering for tabs. Read that first and follow the same approach, it is not HTML5 drag-and-drop and mixing the two would be inconsistent.

The part you cannot copy from it is scrolling. The bookmarks panel sits in a scrollable sidebar, so dragging near the top or bottom edge needs to scroll, and the tab bar never had to deal with that.

tell me here if anything about the store or the persist migration is unclear.