Fix queue loading, null-safe models, autofill, and add outbound dialer

- Fix queue queries in mobile API and SSE to use twp_group_members
  (matching browser phone) instead of twp_queue_assignments
- Auto-create personal queues if user has no extension
- Make all model JSON parsing null-safe (handle null, string ints, bools)
- Add AutofillGroup and autofill hints to login form
- Add outbound calling with dialpad bottom sheet on dashboard

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

mobile/lib/models/queue_state.dart

@@ -15,13 +15,19 @@ class QueueInfo {
 
   factory QueueInfo.fromJson(Map<String, dynamic> json) {
     return QueueInfo(
-      id: json['id'] as int,
-      name: json['name'] as String,
-      type: json['type'] as String,
+      id: _toInt(json['id']),
+      name: (json['name'] ?? '') as String,
+      type: (json['type'] ?? '') as String,
       extension: json['extension'] as String?,
-      waitingCount: json['waiting_count'] as int,
+      waitingCount: _toInt(json['waiting_count']),
     );
   }
+
+  static int _toInt(dynamic value) {
+    if (value is int) return value;
+    if (value is String) return int.tryParse(value) ?? 0;
+    return 0;
+  }
 }
 
 class QueueCall {
@@ -43,12 +49,18 @@ class QueueCall {
 
   factory QueueCall.fromJson(Map<String, dynamic> json) {
     return QueueCall(
-      callSid: json['call_sid'] as String,
-      fromNumber: json['from_number'] as String,
-      toNumber: json['to_number'] as String,
-      position: json['position'] as int,
-      status: json['status'] as String,
-      waitTime: json['wait_time'] as int,
+      callSid: (json['call_sid'] ?? '') as String,
+      fromNumber: (json['from_number'] ?? '') as String,
+      toNumber: (json['to_number'] ?? '') as String,
+      position: _toInt(json['position']),
+      status: (json['status'] ?? '') as String,
+      waitTime: _toInt(json['wait_time']),
     );
   }
+
+  static int _toInt(dynamic value) {
+    if (value is int) return value;
+    if (value is String) return int.tryParse(value) ?? 0;
+    return 0;
+  }
 }