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/calendar_manager.py

@@ -111,60 +111,38 @@ class CalendarManager(BaseServiceManager):
             return False
 
     def _test_service_connectivity(self) -> Dict[str, Any]:
-        """Test calendar service connectivity"""
+        """Test calendar service connectivity via TCP socket to cell-radicale container."""
+        import socket
         try:
-            # Test connection to calendar service
-            result = subprocess.run(['curl', '-s', 'http://localhost:5232'], 
-                                  capture_output=True, text=True, timeout=5)
-            
-            success = result.returncode == 0 and result.stdout.strip()
-            return {
-                'success': success,
-                'message': 'Calendar service accessible' if success else 'Calendar service not accessible'
-            }
+            with socket.create_connection(('cell-radicale', 5232), timeout=5):
+                pass
+            return {'success': True, 'message': 'Calendar service accessible'}
         except Exception as e:
-            return {
-                'success': False,
-                'message': f'Service test error: {str(e)}'
-            }
+            return {'success': False, 'message': f'Calendar service not accessible: {str(e)}'}
 
     def _test_database_connectivity(self) -> Dict[str, Any]:
-        """Test database connectivity"""
+        """Test database connectivity — data dir must be writable; files are created on first use."""
         try:
-            # Check if data files are accessible
-            files_exist = all([
-                os.path.exists(self.users_file),
-                os.path.exists(self.calendars_file),
-                os.path.exists(self.events_file)
-            ])
-            
+            data_dir = os.path.dirname(self.users_file)
+            os.makedirs(data_dir, exist_ok=True)
+            accessible = os.access(data_dir, os.R_OK | os.W_OK)
             return {
-                'success': files_exist,
-                'message': 'Database files accessible' if files_exist else 'Database files not accessible'
+                'success': accessible,
+                'message': 'Database directory accessible' if accessible else 'Database directory not accessible'
             }
         except Exception as e:
-            return {
-                'success': False,
-                'message': f'Database test error: {str(e)}'
-            }
+            return {'success': False, 'message': f'Database test error: {str(e)}'}
 
     def _test_web_interface(self) -> Dict[str, Any]:
-        """Test web interface connectivity"""
+        """Test Radicale web interface via HTTP to cell-radicale container."""
         try:
-            # Test web interface connection
-            result = subprocess.run(['curl', '-s', 'http://localhost:5232'], 
-                                  capture_output=True, text=True, timeout=5)
-            
-            success = result.returncode == 0 and 'radicale' in result.stdout.lower()
-            return {
-                'success': success,
-                'message': 'Web interface accessible' if success else 'Web interface not accessible'
-            }
+            import urllib.request
+            with urllib.request.urlopen('http://cell-radicale:5232', timeout=5) as r:
+                body = r.read(512).decode('utf-8', errors='ignore').lower()
+            success = r.status < 500
+            return {'success': success, 'message': 'Web interface accessible' if success else 'Web interface not accessible'}
         except Exception as e:
-            return {
-                'success': False,
-                'message': f'Web interface test error: {str(e)}'
-            }
+            return {'success': False, 'message': f'Web interface not accessible: {str(e)}'}
 
     def _load_users(self) -> List[Dict[str, Any]]:
         """Load calendar users from file"""