chore: Add Additional Contact APIs (#1130)

Co-authored-by: Pranav Raj Sreepuram <pranavrajs@gmail.com>

app/controllers/api/v1/accounts/contacts/contact_inboxes_controller.rb

@@ -0,0 +1,26 @@
+class Api::V1::Accounts::Contacts::ContactInboxesController < Api::V1::Accounts::BaseController
+  before_action :ensure_contact
+  before_action :ensure_inbox, only: [:create]
+  before_action :validate_channel_type
+
+  def create
+    source_id = params[:source_id] || SecureRandom.uuid
+    @contact_inbox = ContactInbox.create(contact: @contact, inbox: @inbox, source_id: source_id)
+  end
+
+  private
+
+  def validate_channel_type
+    return if @inbox.channel_type == 'Channel::Api'
+
+    render json: { error: 'Contact Inbox creation is only allowed in API inboxes' }, status: :unprocessable_entity
+  end
+
+  def ensure_inbox
+    @inbox = Current.account.inboxes.find(params[:inbox_id])
+  end
+
+  def ensure_contact
+    @contact = Current.account.contacts.find(params[:contact_id])
+  end
+end