feat(device): replace daily wakeHour with multi-time wakeTimes (minutes)

Frame settings now offer two update-frequency modes: "at specific times" or
"every X minutes". Times are stored as an int[] of minutes-since-midnight,
allowing multiple slots per day at minute granularity. Backend computes the
earliest upcoming slot for X-Interval-Ms and uses the most-recent-past slot
as the rotation-due boundary. PWA settings sheet has hour/minute/AM-PM
dropdowns with + Add / trash, a live "next update" preview, and a note
that changes only take effect at the device's next sync.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Schedule.php

@@ -20,8 +20,9 @@ class Schedule implements ScheduleProviderInterface
     public function getSchedule(): SymfonySchedule
     {
         // Rotation is handled at poll time in DeviceImageController — no scheduler needed.
-        // DEV/PROD note: when switching to wakeHour mode, the device only polls once per day,
-        // so rotation still happens correctly (isDue() fires on that single daily poll).
+        // DEV/PROD note: when switching to wakeTimes mode, the device only polls
+        // at each configured time, so rotation still happens correctly (isDue()
+        // fires on each scheduled poll).
         return (new SymfonySchedule())
             ->stateful($this->cache)
             ->processOnlyLastMissedRun(true)