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/locale/de/LC_MESSAGES/django.po

@@ -340,9 +340,6 @@ msgstr "Geräte"
 msgid "Dimensions"
 msgstr "Abmessungen"
 
-msgid "Drag devices to move them"
-msgstr "Geräte zum Verschieben ziehen"
-
 msgid "Draw.io (.drawio)"
 msgstr "Draw.io (.drawio)"
 
@@ -926,3 +923,8 @@ msgid "{{ counter }} planned device will be created per rack."
 msgid_plural "{{ counter }} planned devices will be created per rack."
 msgstr[0] "Pro Rack wird {{ counter }} geplantes Gerät angelegt."
 msgstr[1] "Pro Rack werden {{ counter }} geplante Geräte angelegt."
+
+msgid "Drag devices to move or flip them between front and rear"
+msgstr ""
+"Geräte ziehen, um sie zu verschieben oder zwischen Front und Rückseite zu "
+"wechseln"