fix: all service pages use live domain; cell_name/domain propagate to DNS; /api/status reads stored identity

Changes:
- ConfigContext.jsx: React context that loads /api/config once; exposes domain,
  cell_name, refresh() — wraps entire app in App.jsx
- Email/Calendar/Files pages: replace hardcoded 'mail.cell', 'calendar.cell',
  'files.cell', 'webdav.cell' with domain from ConfigContext; hostname updates
  immediately after Settings save (refreshConfig() called on save)
- /api/status: cell_name and domain now read from stored _identity in config_manager,
  not hardcoded 'personal-internet-cell' / 'cell.local'
- network_manager.apply_cell_name(old, new): updates hostname A-record in primary
  zone file and reloads CoreDNS; called from PUT /api/config when cell_name changes
- Old identity captured before save so apply_cell_name gets the correct old value
- Settings EmailForm: smtp/imap ports are read-only with note (docker-compose.yml level)
- Settings FilesForm: port is read-only with note (Caddy proxies on 80 externally)
- Settings CalendarForm: port labeled "Internal port; clients use 80 via Caddy"

Tests added:
- test_apply_cell_name_renames_host_record
- test_apply_cell_name_noop_when_same

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

api/app.py

@@ -356,9 +356,10 @@ def get_cell_status():
         current_time = time.time()
         uptime_seconds = int(current_time - API_START_TIME)
         
+        identity = config_manager.configs.get('_identity', {})
         return jsonify({
-            "cell_name": "personal-internet-cell",
-            "domain": "cell.local",
+            "cell_name": identity.get('cell_name', os.environ.get('CELL_NAME', 'mycell')),
+            "domain": identity.get('domain', os.environ.get('CELL_DOMAIN', 'cell')),
             "uptime": uptime_seconds,
             "peers_count": len(peers),
             "services": services_status,
@@ -397,6 +398,8 @@ def update_config():
         # Handle identity fields (cell_name, domain, ip_range, wireguard_port)
         identity_keys = {'cell_name', 'domain', 'ip_range', 'wireguard_port'}
         identity_updates = {k: v for k, v in data.items() if k in identity_keys}
+        # Capture old identity BEFORE saving, for apply_cell_name comparison
+        old_identity = dict(config_manager.configs.get('_identity', {}))
         if identity_updates:
             stored = config_manager.configs.get('_identity', {})
             stored.update(identity_updates)
@@ -439,6 +442,15 @@ def update_config():
             all_restarted.extend(net_result.get('restarted', []))
             all_warnings.extend(net_result.get('warnings', []))
 
+        # Apply cell name change to DNS hostname record
+        if identity_updates.get('cell_name'):
+            old_name = old_identity.get('cell_name', os.environ.get('CELL_NAME', 'mycell'))
+            new_name = identity_updates['cell_name']
+            if old_name != new_name:
+                cn_result = network_manager.apply_cell_name(old_name, new_name)
+                all_restarted.extend(cn_result.get('restarted', []))
+                all_warnings.extend(cn_result.get('warnings', []))
+
         logger.info(f"Updated config, restarted: {all_restarted}")
         return jsonify({
             "message": "Configuration updated and applied",

api/network_manager.py

@@ -422,6 +422,36 @@ class NetworkManager(BaseServiceManager):
             warnings.append(f"CoreDNS reload failed: {e}")
 
         return {'restarted': restarted, 'warnings': warnings}
+
+    def apply_cell_name(self, old_name: str, new_name: str) -> Dict[str, Any]:
+        """Update the cell hostname record in the primary DNS zone file."""
+        restarted = []
+        warnings = []
+        if not old_name or not new_name or old_name == new_name:
+            return {'restarted': restarted, 'warnings': warnings}
+        try:
+            dns_data = os.path.join(self.data_dir, 'dns')
+            if os.path.isdir(dns_data):
+                for fname in os.listdir(dns_data):
+                    if fname.endswith('.zone') and 'local' not in fname:
+                        zone_file = os.path.join(dns_data, fname)
+                        with open(zone_file) as f:
+                            content = f.read()
+                        # Replace hostname record: old_name  IN A ...
+                        import re
+                        content = re.sub(
+                            rf'^{re.escape(old_name)}(\s+IN\s+A\s+)',
+                            f'{new_name}\\1',
+                            content, flags=re.MULTILINE
+                        )
+                        with open(zone_file, 'w') as f:
+                            f.write(content)
+                        break
+            self._reload_dns_service()
+            restarted.append('cell-dns (reloaded)')
+        except Exception as e:
+            warnings.append(f"cell_name DNS update failed: {e}")
+        return {'restarted': restarted, 'warnings': warnings}
     
     def test_dns_resolution(self, domain: str) -> Dict:
         """Test DNS resolution for a domain using Python socket."""