v0.2.2: support dragging a device between front and rear elevations

Front and rear panels already share one coordinate system (same
UNIT_HEIGHT, RACK_X, ...), just placed side by side on screen, so the
existing delta-based drag math is equally valid for a drop on the
other panel - only needed to detect which face the pointer ended up
over (elementFromPoint at drop time) and include it as `face` in the
submitted move; the reorder endpoint already supported changing it.

Also fixed a bug this surfaced: without pointer-events: none on the
dragged block during the drag, elementFromPoint() at drop time always
hit the dragged block itself (it's what's rendered under the cursor),
never the panel actually underneath - cross-face drops would never
have been detected. Pointer capture keeps delivering move/up events to
the block regardless of its own pointer-events value, so this is safe.

Added overflow: visible on the elevation SVGs so a device being
dragged toward the other panel doesn't just vanish at its own SVG's
edge mid-drag.

Updated the German translation for the changed drag-hint string.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -1,5 +1,17 @@
 # Changelog
 
+## 0.2.2
+
+- Drag-and-drop now supports dragging a device from the front elevation onto the rear
+  one (and back), reassigning its face. Front and rear share one coordinate system
+  (same unit height, rack offset, ...), just placed side by side on screen, so the
+  existing delta-based drag math is already valid for a cross-panel drop - only the
+  target face needed detecting (via `elementFromPoint` at drop time) and sending along.
+  Fixed a related bug along the way: without `pointer-events: none` on the dragged
+  block during the drag, `elementFromPoint` would always hit the dragged block itself
+  rather than the panel underneath, so the cross-face drop would never have been
+  detected; pointer capture keeps delivering move/up events to it regardless.
+
 ## 0.2.1
 
 - Rework PNG export: instead of rasterizing the SVG export via `<img>`/`<canvas>`