* feat(3cx): sync office department BLFs via XAPI
Keep unlock and lockdown keys in the templates and write colleague plus shared-parking BLFs per extension so phones skip their own line.
* fix(3cx): preserve parking BLF IDs and fail the job on PATCH errors
- Backlight dims to level 1 after 5 min, never fully sleeps
- Screensaver and power saving disabled
- README updated with T54W references and SP template manual steps
Two variants:
- yealinkT54W-door-unlock.ph.xml — line key 2 as door unlock URL
- yealinkT54W-door-unlock-with-sp.ph.xml — line key 2 as door unlock, keys 3-5 as shared parking SP1-3
