Recompute next_run_at when re-enabling a paused recurring schedule (#89)

toggleActive() flipped is_active without touching next_run_at. If a
schedule was disabled while next_run_at was still in the future, then
re-enabled after that date had passed, the next cron tick saw
next_run_at <= NOW() and fired immediately — surprising for an admin
expecting a re-enabled "daily" schedule to wait until its next natural
occurrence. Now recomputes next_run_at from the current time when
transitioning to active, matching what a fresh schedule creation would
produce; disabling is unchanged.

Verified against a local MariaDB instance: re-enabling a schedule
whose next_run_at was in 2020 recomputed it to tomorrow at the
scheduled time; disabling leaves next_run_at untouched.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MGDKHiU5RJdo3dqQUDow3X

models/RecurringTicketModel.php

@@ -231,9 +231,33 @@ class RecurringTicketModel
      */
     public function toggleActive($recurringId)
     {
-        $sql = "UPDATE recurring_tickets SET is_active = NOT is_active WHERE recurring_id = ?";
+        $recurring = $this->getById($recurringId);
-        $stmt = $this->conn->prepare($sql);
+        if (!$recurring) {
-        $stmt->bind_param('i', $recurringId);
+            return ['success' => false];
+        }
+
+        $newActive = $recurring['is_active'] ? 0 : 1;
+
+        if ($newActive) {
+            // Re-enabling: recompute next_run_at from now, as if the schedule
+            // were freshly created. Otherwise a schedule paused while
+            // next_run_at was still in the future, then re-enabled after that
+            // date has passed, would fire immediately on the next cron tick
+            // instead of waiting for its next natural occurrence.
+            $nextRun = $this->calculateNextRunTime(
+                $recurring['schedule_type'],
+                $recurring['schedule_day'],
+                $recurring['schedule_time']
+            );
+            $sql = "UPDATE recurring_tickets SET is_active = ?, next_run_at = ? WHERE recurring_id = ?";
+            $stmt = $this->conn->prepare($sql);
+            $stmt->bind_param('isi', $newActive, $nextRun, $recurringId);
+        } else {
+            $sql = "UPDATE recurring_tickets SET is_active = ? WHERE recurring_id = ?";
+            $stmt = $this->conn->prepare($sql);
+            $stmt->bind_param('ii', $newActive, $recurringId);
+        }
+
         $success = $stmt->execute();
         $stmt->close();
         return ['success' => $success];