Allow AP phone number as alternative to AP email (#17)

[gutobenn]

Which issue does this close?

Closes #17

Write a short description of code change.

Adds phone-number support to accounts-payable contacts across prospects, distributor customers, and active Fulfil customers. AP rows now satisfy the "AP contact required" rule with an email, a phone (stored as E.164 via propaganistas/laravel-phone), or both — the legacy {name, value} shape (email or AP Portal URL) continues to work. FulfilService reads and writes phone-typed party.contact_mechanism rows alongside email, deduping by contact name on read. When AR automation fires for a customer that has no AP email but does have a phone, it swaps the customer-facing template for a new internal ap_phone_followup_required template routed to accountsreceivable@universalyums.com so the AR team can call instead.

How should these changes be tested?

• Active customer: open an AP contact, add a phone in E.164 format, save — confirm it round-trips to Fulfil as a phone-typed contact mechanism.
• Active customer: create an AP contact with phone only (no email) — confirm validation passes and the phone appears on reload.
• Distributor customer: add a contact via the inline form with only a phone — confirm it saves.
• Prospect: add an AP contact with phone only — confirm save, then promote the prospect and verify the phone reaches Fulfil.
• AR automation dry-run on a phone-only customer — confirm the "AP Phone Follow-up Required" template is sent to the AR inbox with the phone surfaced in the body, instead of going to the customer.
• Existing AP contacts (legacy {name, value: email}) still render and save unchanged.

Steps taken before assigning the PR.

• Reviewed the changeset in this PR.
• Initial code review by Claude.