refactor: remove redundant cancel button from password change form

The "Annuleren" button served no purpose — there's no prior state to
revert to in a password change form. The fields are already empty on
load and the type="reset" just cleared them to the same empty state.

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

apps/app/src/components/account-settings/SecurityTab.vue

@@ -242,21 +242,13 @@ function copyRegeneratedCodes() {
         </VList>
       </VCardText>
 
-      <VCardText class="d-flex flex-wrap gap-4">
+      <VCardText>
         <VBtn
           type="submit"
           :loading="changePasswordMutation.isPending.value"
         >
           Wachtwoord wijzigen
         </VBtn>
-        <VBtn
-          color="secondary"
-          variant="tonal"
-          type="reset"
-          @click="passwordForm = { current_password: '', password: '', password_confirmation: '' }; passwordSuccess = ''"
-        >
-          Annuleren
-        </VBtn>
       </VCardText>
     </VForm>
   </VCard>