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/agent_status.dart

@@ -17,11 +17,11 @@ class AgentStatus {
 
   factory AgentStatus.fromJson(Map<String, dynamic> json) {
     return AgentStatus(
-      status: _parseStatus(json['status'] as String),
-      isLoggedIn: json['is_logged_in'] as bool,
+      status: _parseStatus((json['status'] ?? 'offline') as String),
+      isLoggedIn: json['is_logged_in'] == true || json['is_logged_in'] == 1 || json['is_logged_in'] == '1',
       currentCallSid: json['current_call_sid'] as String?,
       lastActivity: json['last_activity'] as String?,
-      availableForQueues: json['available_for_queues'] as bool? ?? true,
+      availableForQueues: json['available_for_queues'] != false && json['available_for_queues'] != 0 && json['available_for_queues'] != '0',
     );
   }