partner_invoicing_mode_monthly

Purpose

Enable automatic monthly invoicing for customers configured with a monthly invoicing mode.

Features

res.partner: Adds a "Monthly" invoicing mode option so customers can be billed once per month.
res.company: Stores the day of the month for monthly invoicing and records when the process last ran at company level.
res.config.settings: Lets administrators configure the monthly invoicing day and review the last execution directly from the settings interface.
sale.order: Implements cron-driven monthly invoice generation by delegating to the generic invoice creation flow for partners in monthly mode.
sale.order: Identifies companies requiring monthly invoicing by checking missed months and handling end-of-month fallback days.
automation: Registers a daily cron job that triggers the monthly invoice generation routine for all eligible companies.
queue.job: Defines a dedicated job channel and function so monthly invoice generation runs through the queue system.