fix: health history all-down — connectivity checks and UI data path

Service manager fixes (connectivity tests):
- email_manager: replace telnet with socket.create_connection for SMTP/IMAP;
  replace nslookup with socket.getaddrinfo for DNS; exclude unconfigured domain
  from success (email healthy=False now correctly means ports refused, not missing domain)
- calendar_manager: replace localhost:5232 with cell-radicale:5232;
  fix database check to test dir writability instead of file existence (files created on demand)
- file_manager: replace localhost:8080 with cell-webdav:80; add top-level success key
- network_manager: replace nslookup with socket.getaddrinfo;
  add success key to dhcp_test and ntp_test return values
- routing_manager: exclude iptables_access from success
  (iptables runs in cell-wireguard, not API container)
- wireguard_manager: add success key to no-arg test_connectivity result

Health history UI:
- SvcCol reads data?.status?.running || data?.status?.status — handles nested health check shape

Result: network/wireguard/calendar/files/routing/vault all healthy=True.
Email healthy=False is correct — mail server needs ≥1 account before Dovecot starts.

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

api/network_manager.py

@@ -292,23 +292,14 @@ class NetworkManager(BaseServiceManager):
             logger.error(f"Failed to reload DHCP service: {e}")
     
     def test_dns_resolution(self, domain: str) -> Dict:
-        """Test DNS resolution for a domain"""
+        """Test DNS resolution for a domain using Python socket."""
+        import socket
         try:
-            result = subprocess.run(['nslookup', domain, '127.0.0.1'], 
-                                  capture_output=True, text=True, timeout=10)
-            
-            return {
-                'success': result.returncode == 0,
-                'output': result.stdout,
-                'error': result.stderr
-            }
-            
+            results = socket.getaddrinfo(domain, None)
+            addrs = [r[4][0] for r in results]
+            return {'success': True, 'output': f"Resolved: {', '.join(addrs)}", 'error': ''}
         except Exception as e:
-            return {
-                'success': False,
-                'output': '',
-                'error': str(e)
-            }
+            return {'success': False, 'output': '', 'error': str(e)}
     
     def test_dhcp_functionality(self) -> Dict:
         """Test DHCP functionality"""
@@ -323,14 +314,15 @@ class NetworkManager(BaseServiceManager):
             leases = self.get_dhcp_leases()
             
             return {
+                'success': is_running,
                 'running': is_running,
                 'leases_count': len(leases),
                 'leases': leases
             }
-            
+
         except Exception as e:
             logger.error(f"Failed to test DHCP functionality: {e}")
-            return {'running': False, 'leases_count': 0, 'leases': []}
+            return {'success': False, 'running': False, 'leases_count': 0, 'leases': []}
     
     def test_ntp_functionality(self) -> Dict:
         """Test NTP functionality"""
@@ -354,13 +346,14 @@ class NetworkManager(BaseServiceManager):
                     ntp_test['error'] = str(e)
             
             return {
+                'success': is_running,
                 'running': is_running,
                 'ntp_test': ntp_test
             }
-            
+
         except Exception as e:
             logger.error(f"Failed to test NTP functionality: {e}")
-            return {'running': False, 'ntp_test': {}} 
+            return {'success': False, 'running': False, 'ntp_test': {}} 
 
     def get_network_info(self) -> dict:
         """Return general network info: IP addresses, interfaces, gateway, DNS, etc."""