Fix double /api/ prefix in API endpoint calls

When VITE_API_URL=/api, axios baseURL is already set to /api. However, all endpoint calls included the /api/ prefix, creating double paths like /api/api/auth/login/.

Removed /api/ prefix from 81 API endpoint calls across 22 files:
- src/api/auth.ts - Fixed login, logout, me, refresh, hijack endpoints
- src/api/client.ts - Fixed token refresh endpoint
- src/api/profile.ts - Fixed all profile, email, password, MFA, sessions endpoints
- src/hooks/*.ts - Fixed all remaining API calls (users, appointments, resources, etc)
- src/pages/*.tsx - Fixed signup and email verification endpoints

This ensures API requests use the correct path: /api/auth/login/ instead of /api/api/auth/login/

🤖 Generated with Claude Code

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

frontend/src/api/platformOAuth.ts

@@ -75,7 +75,7 @@ export interface PlatformOAuthSettingsUpdate {
  * Get platform OAuth settings
  */
 export const getPlatformOAuthSettings = async (): Promise<PlatformOAuthSettings> => {
-  const { data } = await apiClient.get('/api/platform/settings/oauth/');
+  const { data } = await apiClient.get('/platform/settings/oauth/');
   return data;
 };
 
@@ -85,6 +85,6 @@ export const getPlatformOAuthSettings = async (): Promise<PlatformOAuthSettings>
 export const updatePlatformOAuthSettings = async (
   settings: PlatformOAuthSettingsUpdate
 ): Promise<PlatformOAuthSettings> => {
-  const { data } = await apiClient.post('/api/platform/settings/oauth/', settings);
+  const { data } = await apiClient.post('/platform/settings/oauth/', settings);
   return data;
 };