fix: Enhance cron jobs and have an outside report button on sales invoice

[maniamartial]

• send_multiple_signed_compliance_invoices_to_zatca (still the method registered on Scheduled Job Type) now only frappe.enqueues the real work.
• _run_send_multiple_signed_compliance_invoices_to_zatca holds the previous logic (loop companies → invoices → bg_generate_einvoice), runs in a worker, and ends naturally when there is nothing left to process (same as before, just not on the scheduler process).

Worker settings

• queue="long" – use the long worker so jobs are not stuck on the default queue.

• timeout=1800 (30 minutes) – passed explicitly so the job can run up to 30 minutes even though Frappe’s default long queue timeout is 25 minutes (1500 s).

• deduplicate=True with job_id="zatca_integration:b2c_compliance_batch_submit" – if the scheduler fires again while a batch is queued or running, Frappe will not enqueue a second copy (avoids overlapping batches).

• onload: inner button “ZATCA Report” on the list page (same bar as other list actions).

• Uses row checkboxes → get_checked_items(true) for names.

• Asks for confirmation, freezes the screen with “Reporting to ZATCA…”, calls the bulk method, then shows a wide summary (Succeeded / Skipped / Failed) and refreshes the list.