Write NTAG213/215/216 tags for third-party spools via the SpoolBuddy
kiosk UI. New "Write" page with three workflows: existing spool, new
spool creation, and tag replacement. Backend encodes 133-byte OpenTag3D
NDEF payloads (material, color, brand, weight, temp). Daemon writes
page-by-page via PN5180 NTAG WRITE command with read-back verification.
Write commands flow through heartbeat polling with WebSocket status
updates. Includes 39 new tests and translations for all 6 languages.