plip_ui.{h,c}: LVGL phone on the BOX-3 LCD driven by the plip_virtual
hook state. Idle/ringing shows a phone glyph + status ("Appel
entrant…"); off-hook shows a 3x4 dial keypad (1-9,*,0,#) with a live
number field. A fixed bottom touch button toggles the hook —
"Décrocher" (green) while ringing, "Raccrocher" (red) off-hook,
disabled when idle. Dialed digits are reported to the master
(reason "dial:<n>") and surfaced in GET /status.
plip_virtual gains the public pickup/hangup/dial API, a state
callback for the UI, and a state getter; enables Montserrat 24/48.
Build green; flashed and verified on a real ESP32-S3-BOX-3.
Claude Worker claude2