Align bulk contact create/update fields with the single contact endpoints

Adds avatar, owner_id, unsubscribed_from_emails, and tags (add/remove) to
bulk create/update request bodies to match the single contact create/update
endpoints. Renames the update identifier field to external_id and owner_id
to string to match the rest of the contact schemas, drops the undocumented
companies/company properties, and clarifies tag id requirements and
best-effort application behavior.

Author: VarshSuresh

descriptions/0/api.intercom.io.yaml

@@ -26958,6 +26958,10 @@ components:
               phone:
                 type: string
                 description: The contact's phone number.
+              avatar:
+                type: string
+                description: An image URL containing the avatar of the contact.
+                example: https://www.example.com/avatar_image.jpg
               language_override:
                 type: string
                 description: A preferred language setting for the contact, used by
@@ -26973,6 +26977,32 @@ components:
                 type: integer
                 description: The time the contact was last seen, in Unix timestamp
                   format.
+              owner_id:
+                type: string
+                description: The ID of an admin that has been assigned account ownership
+                  of the contact.
+                example: "321"
+              unsubscribed_from_emails:
+                type: boolean
+                description: Whether the contact is unsubscribed from emails.
+                example: true
+              tags:
+                type: object
+                description: |
+                  Tags to add to the contact. Each tag is identified by its `id`, which must be a positive integer for a tag that already exists in your workspace. Tag application is best-effort: unknown tag IDs are skipped while the rest of the contact create still applies. Per-tag results are not yet returned in the job status.
+                properties:
+                  add:
+                    type: array
+                    description: Tags to add to the contact.
+                    items:
+                      type: object
+                      required:
+                      - id
+                      properties:
+                        id:
+                          type: string
+                          description: The ID of an existing tag to add to the contact.
+                          example: '123'
         job:
           type: object
           description: Optional. Include to append tasks to an existing job.
@@ -27044,55 +27074,31 @@ components:
                 description: A preferred language setting for the contact, used by
                   the Intercom Messenger.
                 example: fr
-              user_id:
+              external_id:
                 type: string
-                description: A unique identifier for the contact that you provide. Maps to the contact's external user ID.
-                example: '25'
+                description: A unique identifier for the contact which you have
+                  defined.
+                example: abc123
               phone:
                 type: string
                 description: The contact's phone number.
                 example: "+353871234567"
               owner_id:
-                type: integer
-                description: The ID of the teammate who owns the contact.
-                example: 123
+                type: string
+                description: The ID of an admin that has been assigned account ownership
+                  of the contact.
+                example: "321"
               unsubscribed_from_emails:
                 type: boolean
                 description: Whether the contact is unsubscribed from emails.
                 example: true
               avatar:
                 type: string
-                description: An image URL for the contact's avatar. You can also pass an object with an `image_url` field.
-                example: https://www.example.com/avatar.png
+                description: An image URL containing the avatar of the contact.
+                example: https://www.example.com/avatar_image.jpg
               custom_attributes:
                 type: object
                 description: Custom attributes to update on the contact.
-              companies:
-                type: array
-                description: A list of companies to associate with the contact. Each company is identified by the `company_id` you have defined. Companies that do not exist are created.
-                items:
-                  type: object
-                  properties:
-                    company_id:
-                      type: string
-                      description: The company ID you have defined for the company.
-                      example: '6'
-                    name:
-                      type: string
-                      description: The name of the company.
-                      example: Blue Sun
-              company:
-                type: object
-                description: A single company to associate with the contact, identified by the `company_id` you have defined. Created if it does not exist.
-                properties:
-                  company_id:
-                    type: string
-                    description: The company ID you have defined for the company.
-                    example: '6'
-                  name:
-                    type: string
-                    description: The name of the company.
-                    example: Blue Sun
               tags:
                 type: object
                 description: |
@@ -27121,7 +27127,7 @@ components:
                         id:
                           type: string
                           description: The ID of an existing tag to remove from the contact.
-                          example: '456'
+                          example: '789'
         job:
           type: object
           description: Optional. Include to append tasks to an existing job.