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>

netbox_rack_concept/__init__.py

@@ -1,6 +1,6 @@
 from netbox.plugins import PluginConfig
 
-__version__ = '0.2.1'
+__version__ = '0.2.2'
 
 
 class RackConceptConfig(PluginConfig):