CC2 ↔ Spoolman bridge with NFC tag generator

- Reads /opt/usr/canvas_record_info.json over SSH (pinned host key,
  restricted key), decodes Spoolman spool ids from the tag weight
- Mirrors spools into CC2 Control's spool library and assigns slots,
  keeps its own slot mapping, sets Spoolman locations
- Books the drop of CC2 Control's measured remaining weight to Spoolman
  after each print, idempotent across restarts and interrupted bookings
- Dry-run by default; web UI for settings, SSH key, status and log
- Tag generator for NFC Tools command chains (NTAG213/215/216)
- Tests, mock environment, Dockerfile, Gitea Actions CI

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014GcEk5tkfFSYD6NTF66NkC

.env.example

@@ -0,0 +1,17 @@
+# Startwerte. Nach dem ersten Start gelten die Einstellungen aus der Oberfläche (/data/settings.json).
+PRINTER_HOST=10.10.2.202
+SSH_PORT=22
+SSH_USER=root
+CC2_URL=http://10.10.2.202:8081
+SPOOLMAN_URL=http://10.10.6.10:7912
+ID_OFFSET=10000
+POLL_INTERVAL=5
+# Dry-Run ist Standard; ausschalten nur über die Oberfläche.
+DRY_RUN=true
+
+# Optionaler Basic-Auth-Schutz der Oberfläche (beide setzen, um ihn zu aktivieren):
+# BRIDGE_USER=admin
+# BRIDGE_PASSWORD=ein-langes-passwort
+
+# PORT=5066
+# LOG_LEVEL=INFO