Add ModeTemplate with Svelte 5 frontend and components

- Create reusable components: auth, api-client, shared-types
- ModeTemplate with Hono backend and SvelteKit frontend
- Auth store refactored to class-based Svelte 5 pattern
- SSR-safe hydrate() pattern for localStorage access
- Frontend builds successfully with Svelte 5 runes

components/auth/index.ts

@@ -0,0 +1,28 @@
+export { 
+  getAuthUrl, 
+  handleCallback,
+  exchangeCodeForToken,
+  getMicrosoftUserInfo,
+  getPocketBaseToken,
+  getConfigFromEnv,
+} from './microsoft-oauth';
+
+export type { 
+  AuthResult, 
+  OAuthConfig 
+} from './microsoft-oauth';
+
+export {
+  HEADERS,
+  CONTENT_TYPES,
+  STORAGE_KEYS,
+  pbAuthHeader,
+  pbHeaders,
+  isSessionExpired,
+} from './types';
+
+export type {
+  MicrosoftTokens,
+  PocketBaseTokens,
+  AuthSession,
+} from './types';