feat: account settings with Vuexy tab pattern and MFA banner fix

Restructures account/profile pages to match Vuexy's account-settings
tab pattern (Account, Security, Notifications) and fixes the MFA
enforcement banner that stayed visible after successful setup.

Backend:
- Add phone column to users table with migration
- Add PUT /me/profile endpoint for profile updates
- Create UpdateProfileRequest form request
- Update MeResource to include phone field

Organizer app:
- Rewrite account-settings as tabbed page (VTabs pill style + VWindow)
- Create AccountTab: avatar, profile form, email change, danger zone
- Create SecurityTab: password change, MFA method cards, backup codes,
  trusted devices, disable MFA danger zone
- Create NotificationsTab: placeholder with disabled toggles
- Fix MFA banner: set authStore.mfaSetupRequired = false on setup complete
- Update router guard to redirect to ?tab=security for MFA enforcement
- Update UserProfile menu links to use tab query params

Portal:
- Restructure profiel.vue with VTabs (Mijn profiel + Beveiliging)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/routes/api.php

@@ -144,6 +144,7 @@ Route::middleware('auth:sanctum')->group(function () {
     Route::delete('auth/trusted-devices', [TrustedDeviceController::class, 'destroyAll']);
 
     // Account management (self-service)
+    Route::put('me/profile', [AccountController::class, 'updateProfile']);
     Route::post('me/change-password', [AccountController::class, 'changePassword']);
     Route::post('me/change-email', [EmailChangeController::class, 'request']);