fix(contacts): show BSUID-only WhatsApp contacts - #15547

When WhatsApp provides only a BSUID, the Chatwoot contact may have no phone number, email address, or external identifier. The conversation remains accessible, but the contact is excluded by the resolved-contact scope and consequently disappears from Contacts, search results, filters, and exports.

This PR treats an attached WhatsApp ContactInbox as a valid contact identity. BSUID-only customers therefore remain visible across the contact-management surfaces for both Meta Cloud and Twilio WhatsApp.

What changed

• Include contacts with a Meta Cloud WhatsApp ContactInbox in the resolved-contact scope.
• Include contacts from Twilio inboxes whose medium is WhatsApp.
• Apply the same behavior to existing visitor records when CRM v2 is enabled.
• Reuse the shared scope so Contacts, search, filters, and exports remain consistent.
• Continue excluding unidentified contacts from unrelated channels, such as anonymous web-widget visitors.

Things to know

• This changes contact visibility only. It does not merge contacts, promote anonymous visitors, or alter conversation routing.
• This PR is based on #15175. Once that PR is merged, this PR should be retargeted to develop.

How to test

1. Receive a Meta Cloud WhatsApp message that contains a BSUID but no customer phone number.
2. Confirm the resulting contact appears in the Contacts list.
3. Search for the contact by name and apply contact filters.
4. Export contacts and confirm the BSUID-only contact is included.
5. Repeat the flow with a Twilio WhatsApp ExternalUserId and no phone number.
6. Confirm an unidentified web-widget visitor remains excluded.

Fixes

Fixes https://linear.app/chatwoot/issue/CW-7982