fix(rotation): gate poll-driven advance() behind isDue() check

Symptom: with wakeTimes=[4 AM, 9 PM, 9:15 PM], the frame rotated to a
fresh photo at 10:14 AM when the device was reconnected and polled.
The wakeTimes only governed *when* the device polled (via X-Interval-Ms);
they didn't gate whether the server picked a new image when it did.
Power-on or button-press polls would always rotate.

Fix: move the existing isDue() logic from AdvanceRotationMessageHandler
into RotationService as a public method, and gate
DeviceImageController::image so off-schedule polls return the device's
current image (which 304s when X-Current-Image-Id matches) rather than
calling advance(). The scheduler-driven handler still uses the same
isDue — both code paths now share one source of truth.

Tests:
  - DeviceImageControllerTest: new test asserting an off-schedule poll
    returns 304 without rotating; existing wakeTimes tests reworked to
    use slot lists that always have a past slot regardless of run time.
  - AdvanceRotationMessageHandlerTest: existing AR-04 through AR-07
    keep covering isDue's semantics — they now go through the service.

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

src/Service/RotationService.php

@@ -19,6 +19,73 @@ class RotationService
         private readonly LoggerInterface $logger,
     ) {}
 
+    /**
+     * True when the device's configured schedule says a rotation should occur
+     * right now. The contract:
+     *
+     *   - In wakeTimes mode: there must be a wake time that has already passed
+     *     today AND no history entry exists since that boundary.
+     *   - In interval mode: the most recent history entry (if any) must be at
+     *     least `rotationIntervalMinutes` old. A device with no history is due.
+     *
+     * Used by both AdvanceRotationMessageHandler (scheduler-driven) and
+     * DeviceImageController (poll-driven) so off-schedule polls don't
+     * surprise the user with an unrequested rotation — see the user-visible
+     * regression the original poll-rotates-unconditionally code caused.
+     */
+    public function isDue(Device $device): bool
+    {
+        $wakeTimes = $device->getWakeTimes();
+        if (!empty($wakeTimes)) {
+            $tz  = new \DateTimeZone($device->getTimezone());
+            $now = new \DateTimeImmutable('now', $tz);
+
+            // Find the most recent wake time that has already passed today.
+            // If none have hit yet, the next slot is in the future — not due.
+            $boundary = null;
+            foreach ($wakeTimes as $minutes) {
+                $candidate = $now->setTime((int) ($minutes / 60), $minutes % 60, 0);
+                if ($candidate <= $now && ($boundary === null || $candidate > $boundary)) {
+                    $boundary = $candidate;
+                }
+            }
+            if ($boundary === null) {
+                return false;
+            }
+
+            $entry = $this->em->createQueryBuilder()
+                ->select('h')
+                ->from(DeviceImageHistory::class, 'h')
+                ->where('h.device = :device')
+                ->andWhere('h.servedAt >= :wakeTime')
+                ->setParameter('device', $device)
+                ->setParameter('wakeTime', $boundary)
+                ->setMaxResults(1)
+                ->getQuery()
+                ->getOneOrNullResult();
+
+            return $entry === null;
+        }
+
+        // Interval-based: due if last history is older than rotationIntervalMinutes.
+        $last = $this->em->createQueryBuilder()
+            ->select('h')
+            ->from(DeviceImageHistory::class, 'h')
+            ->where('h.device = :device')
+            ->setParameter('device', $device)
+            ->orderBy('h.servedAt', 'DESC')
+            ->setMaxResults(1)
+            ->getQuery()
+            ->getOneOrNullResult();
+
+        if ($last === null) {
+            return true;
+        }
+
+        $elapsed = (new \DateTimeImmutable())->getTimestamp() - $last->getServedAt()->getTimestamp();
+        return $elapsed >= ($device->getRotationIntervalMinutes() * 60);
+    }
+
     /**
      * Select the next image for the device, record history, update currentImage.
      * Returns null if no ready images exist in the pool.