Timers: present each timer and LTC in the Add-tile picker

Adopt main's new multi-tile contract: the module's server exports
tiles() (answered from the poller's held state, never a fresh upstream
request) listing All timers, one entry per discovered timer, and LTC
timecode. The client branches on moduleApi.variant — solo tiles render
exactly one card with no selection menu, and a solo timer that vanishes
from ProPresenter shows a labeled "Not in ProPresenter" card instead of
erroring (visible even in the compact layout). pp-timers-mock gains
--drop=<uuid,...> to simulate a timer deleted in ProPresenter.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

modules/propresenter-timers/style.css

@@ -63,6 +63,7 @@
    that message must never be hidden. */
 [data-module="propresenter-timers"] .tm-compact .tm-card .tm-state { display: none; }
 [data-module="propresenter-timers"] .tm-compact .tm-card-ltc.is-ltc-unavailable .tm-state { display: block; }
+[data-module="propresenter-timers"] .tm-compact .tm-card.is-missing .tm-state { display: block; }
 
 /* ── one timer card ── */
 
@@ -139,6 +140,11 @@
 [data-module="propresenter-timers"] .tm-card.is-complete .tm-time { color: var(--warn); }
 [data-module="propresenter-timers"] .tm-card.is-complete .tm-state { color: var(--warn); }
 
+/* A solo tile whose timer was deleted in ProPresenter. */
+[data-module="propresenter-timers"] .tm-card.is-missing { border-style: dashed; }
+[data-module="propresenter-timers"] .tm-card.is-missing .tm-time { color: var(--muted); }
+[data-module="propresenter-timers"] .tm-card.is-missing .tm-state { color: var(--warn); }
+
 /* Overrun: readable across the room even on a wall display. */
 [data-module="propresenter-timers"] .tm-card.is-overrun {
   border-color: var(--danger);