Rework the site structure tree's drag-and-drop to match Sortable's native
model instead of mid-drag drop zones:
- Drop the dashed empty-list drop zones that appeared on drag start
(flicker, space reservation, and mis-targeted drops: the last item's
child zone sat exactly where 'end of parent list' was).
- Every non-empty list (and the root) ends with a non-draggable ➕ footer
row (vuedraggable #footer slot): click to start a new page at that
level, and while dragging it is the 'end of this list' drop target.
It renders last even mid-drag via flex order, since Sortable appends
end-of-list previews after it in the DOM.
- Dropping ON the lower part of a row makes the page that row's first
child: the child list's container invisibly overlaps its own row's
bottom (negative margin + equal padding, no layout effect) and becomes
hit-testable only while dragging. A row's exposed top strip remains
the 'sibling before' target. Leaf rows work too, creating a sublist.
- Indentation is structural (each nested list margin-indents itself), so
a dragged row previews its whole subtree at the target list's depth.
Rows get a little vertical padding to widen the drop zones.
Reorganize the URL space so all machinery lives under /_/: the Vite
build (now with assetsDir: '', two ES-module entries and hashed shared
assets: style.css, pygments.css, banner.svg, fonts moved from
pagerite/static to frontend/src/assets) is served at /_/assets via
frontend.route(app, "/_/assets") with cached="/", and the admin
shell moves to /_/admin, leaving only "_" as a reserved top-level
slug. A /favicon.ico route serves the file Vite copies from
frontend/public. In dev, Vite proxies content pages and /_/admin to
the backend.
Editor changes: drop the noisy status line for a save-error indicator,
reconnect the WebSocket with exponential backoff, and re-establish the
connection from send() when it has dropped. The socket connects when
an editor is opened (they mount on pen click), not before.
LeoVasanko