Account Portal Invoice Search

This module adds a search box to the "Invoices & Bills" page of the customer portal. Before, portal users could only page through their invoices; now they can type a term and get matching documents.

• The search looks at two things on each invoice: the invoice number (name) and the payment reference (payment_reference). A match on either one is enough.
• The search term is passed through the portal page and applied when Odoo looks up the invoices, so the list, the pager and the page count all reflect the filtered result.
• The search option is labelled "Search in Invoices & Bills" and is registered as a search field on the portal page.

It only changes the customer-facing portal page; it does not add menus, buttons or reports in the backend, and it does not change how invoices are created or posted. Technically it extends the account.move model with a portal search domain and overrides the invoice search, and it extends the portal invoice controller. No new fields, no automatic emails and no scheduled actions are added.