feat: add CalDAV synchronization with automatic sync

- Add CaldavService with tsdav/ical.js for CalDAV server communication
- Add CaldavController, CaldavRepository, and caldav routes
- Add client-side CaldavConfigService with sync(), config CRUD
- Add CalDAV settings UI with config load/save in settings screen
- Sync on login, auto-login (AuthGuard), periodic timer (calendar), and sync button
- Push single events to CalDAV on server-side create/update/delete
- Push all events to CalDAV after chat event confirmation
- Refactor ChatService to use EventService instead of direct EventRepository
- Rename CalDav/calDav to Caldav/caldav for consistent naming
- Add Radicale Docker setup for local CalDAV testing
- Update PlantUML diagrams and CLAUDE.md with CalDAV architecture

apps/client/src/components/BaseButton.tsx

@@ -2,17 +2,18 @@ import { Pressable, Text } from "react-native";
 import { useThemeStore } from "../stores/ThemeStore";
 import { ReactNode } from "react";
 
-type BaseButtonProps = {
+export type BaseButtonProps = {
   children?: ReactNode;
+  className?: string;
   onPress: () => void;
   solid?: boolean;
 };
 
-const BaseButton = ({ children, onPress, solid = false }: BaseButtonProps) => {
+const BaseButton = ({ className, children, onPress, solid = false }: BaseButtonProps) => {
   const { theme } = useThemeStore();
   return (
     <Pressable
-      className="w-11/12 rounded-lg p-4 mb-4 border-4"
+      className={`rounded-lg p-4 mb-4 border-4 ${className}`}
       onPress={onPress}
       style={{
         borderColor: theme.borderPrimary,