Since embedded signup has been disabled on production, WhatsApp inboxes that were created through it have no way to be managed going forward. This PR lets admins transfer an embedded signup inbox to a manual Cloud API setup: the inbox settings Configuration tab now shows the webhook verification token and a "Switch to Manual Setup" form (pre-populated with the Phone Number ID, Business Account ID, and API key stored during the embedded signup journey) instead of the old Reconfigure button. Saving the form updates the channel's `provider_config` without the `source: embedded_signup` marker, so the inbox becomes a regular manually-configured WhatsApp Cloud inbox. The backend re-validates the submitted credentials against Meta before accepting the change. ## How to test 1. Open the settings page of a WhatsApp inbox created via embedded signup → Configuration tab. 2. The Reconfigure button is gone; you see the webhook verification token and a Switch to Manual Setup form pre-filled with the stored credentials. 3. Configure the webhook in your own Meta app using the verification token, enter a permanent access token from that app, and click "Switch to Manual Setup". 4. On success the page switches to the standard manual configuration view (verify token, API key update), and messaging continues to work with the new credentials. Invalid credentials are rejected with an error. ## What changed - `ConfigurationPage.vue`: replaced the embedded-signup Reconfigure section (and the hidden reauthorize component) with the manual transfer form. - New `WHATSAPP_MANUAL_TRANSFER_*` translation keys. --------- Co-authored-by: Muhsin <12408980+muhsin-k@users.noreply.github.com> Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com> Co-authored-by: iamsivin <iamsivin@gmail.com>