Set status P (processing) before send, revert to S on failure

Prevents UI re-trigger while email is in flight. Status flow:
S (scheduled) → P (processing) → D (delivered) / S (failed, retryable)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/send_email.php

@@ -268,7 +268,7 @@ $sql = "
     LEFT JOIN m_patient p
         ON p.M_PatientID = oh.T_OrderHeaderM_PatientID
     WHERE e.T_SendEmailIsActive = 'Y'
-      AND e.T_SendEmailStatus   = 'S'
+      AND e.T_SendEmailStatus   IN ('S')
       AND e.T_SendEmailCount    < {$max_retry}
       {$where_id}
     ORDER BY e.T_SendEmailID ASC
@@ -350,6 +350,14 @@ foreach ($rows as $row) {
         continue;
     }
 
+    // Lock: tandai sedang dikirim agar tidak bisa di-trigger ulang dari UI
+    $pdo->prepare("
+        UPDATE t_send_email
+        SET T_SendEmailStatus      = 'P',
+            T_SendEmailLastUpdated = NOW()
+        WHERE T_SendEmailID = ?
+    ")->execute([$id]);
+
     $err = send_email(
         $smtp,
         $from_addr,
@@ -396,7 +404,8 @@ foreach ($rows as $row) {
         log_msg("  Error: {$err}");
         $pdo->prepare("
             UPDATE t_send_email
-            SET T_SendEmailCount       = T_SendEmailCount + 1,
+            SET T_SendEmailStatus      = 'S',
+                T_SendEmailCount       = T_SendEmailCount + 1,
                 T_SendEmailResponse    = ?,
                 T_SendEmailLastUpdated = NOW()
             WHERE T_SendEmailID = ?