Panel export paths now mirror the server's layout
({exportRoot}/{showId}/[{episode} if episodic]/{shotCode}/{version}) via a new
getShotExportDir helper, so farm and local renders land in the same folder.
Folder creation moves into the per-shot loop so one unwritable path no longer
aborts the whole queue.
Also adds an optional `scene` query param to the ext shots endpoint.
twotalesanimation