Rackpad 1.9.0-beta.1

This beta adds room floorplans after the port/label
batch. Rackpad V2 automation remains deferred.

Choose Floorplan, select a room and explicitly select an existing room
reference image. Upload backgrounds through the room's existing reference-image
controls. Each room has one selected background. Replacing it requires
confirmation and keeps marker coordinates; removing it keeps markers for later
reassignment. Deleting the reference image also clears only the background.

Editors can add markers for racks and devices belonging to that room/lab, drag
markers, use arrow keys (Shift increases the step), change labels and zoom.
Viewers can inspect, zoom and follow inventory links. Markers use normalized image
coordinates. Moving them changes no inventory placement or Rack Studio geometry.
Concurrent edits are rejected and reloaded. Inventory movement to another room
or deletion removes invalid markers in the same database transaction.
Revision tokens roll over at their maximum accepted value, so restored floorplans
can still be edited and inventory cleanup remains atomic; stale edits are rejected.

Schema is 60. Separate settings and marker tables participate in logical and
native recovery, with ownership, coordinate, revision and image validation. Older
backups contain no floorplan settings or markers. Upgrade makes no automatic
background or marker assignments. Rollback requires the previous image/binary
paired with its pre-upgrade database, configuration and encryption key.

The supported scope is one image per room; drawing/CAD, building hierarchies and
automatic placement are excluded. Technical release gates and real installation
acceptance remain separate from synthetic fixtures and publication approval.