Fix notifications fleet alert migration for MySQL and add UI fields

- Change alertscope from JSONB to TEXT for MySQL compatibility
- Add Alert Fleet checkbox, scope, and timeout fields to notification form
- Fields appear conditionally when Alert Fleet is checked

plugins/notifications/frontend/views/NotificationForm.vue

@@ -231,6 +231,34 @@
           </div>
         </div>
 
+        <div v-if="form.alertfleet" class="fleet-alert-options">
+          <div class="form-group">
+            <label for="alertscope">Alert Scope (JSON)</label>
+            <textarea
+              id="alertscope"
+              v-model="alertScopeText"
+              class="form-control"
+              rows="3"
+              :disabled="isDetail"
+              placeholder='{"assettype": "computer", "location": "Building A"}'
+            ></textarea>
+            <small class="form-hint">Optional: Filter alerts by asset type, location, or business unit (JSON format)</small>
+          </div>
+
+          <div class="form-group">
+            <label for="alerttimeout">Auto-dismiss Timeout (minutes)</label>
+            <input
+              id="alerttimeout"
+              v-model.number="form.alerttimeout"
+              type="number"
+              class="form-control"
+              min="0"
+              :disabled="isDetail"
+            />
+            <small class="form-hint">Minutes until auto-dismiss (0 = manual acknowledgment only)</small>
+          </div>
+        </div>
+
         <div v-if="error" class="error-message">{{ error }}</div>
 
         <div class="form-actions">
@@ -304,6 +332,32 @@ const form = ref({
 // site's wall clock, not the viewer's browser zone. Loaded in onMounted.
 const siteTimezone = ref(DEFAULT_TZ)
 
+// Alert scope as text for editing (converts to/from JSON)
+const alertScopeText = ref('')
+
+watch(() => form.value.alertscope, (newVal) => {
+  if (newVal && typeof newVal === 'object') {
+    alertScopeText.value = JSON.stringify(newVal, null, 2)
+  } else if (newVal && typeof newVal === 'string') {
+    alertScopeText.value = newVal
+  } else {
+    alertScopeText.value = ''
+  }
+}, { immediate: true })
+
+watch(alertScopeText, (newVal) => {
+  if (!newVal.trim()) {
+    form.value.alertscope = null
+    return
+  }
+  try {
+    form.value.alertscope = JSON.parse(newVal)
+  } catch (e) {
+    // Keep the text as-is until it's valid JSON
+    form.value.alertscope = newVal
+  }
+})
+
 function selectedTypeName() {
   const selectedType = types.value.find(t => t.notificationtypeid === parseInt(form.value.notificationtypeid))
   return selectedType?.typename?.toLowerCase() || ''