Creates an alert for a specific entity (URL or phone number) within Doppel's Brand Protection product.

Behavior:

• If an alert already exists for the entity, the existing alert is returned (HTTP 200).
• If the alert exists but with a different brand than requested, returns HTTP 409.
• After creation, the alert is automatically processed through Doppel's triage workflow.
• If source is provided, it must exactly match the "API value" field of an external source configured in your organization's settings in Doppel Vision.

Returns HTTP 400 when:

• entity is missing, not a valid URL, or not a valid phone number.
• entity is a protected asset (e.g. google.com).
• tags is not a list of non-empty strings.
• source does not match any configured external source for the organization.
• files contains more than 10 items, duplicate file names, or is missing file_to_upload.