Update doc for Shop PO to Invoice operations flow

Distribution/docs/refactor_docs/shop_po_invoice_operations_flow.md

@@ -35,10 +35,28 @@ status transition and stock movement along the way.
 
 - Created via `ShopPOService.ConfirmAndCreateInvoiceAsync` — confirms the PO **and** creates an
   `Invoice` (`Status: Draft`, `PaymentStatus: Pending`) in one step, linking `ShopPO.InvoiceId`.
-  (No frontend UI currently calls this endpoint — only the plain `Confirm` action is wired up.)
+  The frontend calls it when **Configuration → Invoice Creation** is set to **Auto** (Mode A, the
+  confirm dialog and PO edit page read the mode); with **Manual** (Mode B, the default) it calls the
+  plain `Confirm` and the invoice is created later from `/sales/orders` → **Create Invoice**.
 - Lifecycle: `Draft → Printed → Finalized`.
-  - Finalizing can adjust the billed quantity per line (capped between `0` and the ordered
+  - The invoice has its own lines (`InvoiceItem`), copied from the PO's active lines when it is
-    quantity) and recomputes `TotalAmount` from the adjusted lines.
+    created (either mode). The PO's original quantity stays on `ShopPOItem` and is shown as
+    `orderedQuantity`.
+  - While `Draft`, lines can be edited (`PUT /invoices/{id}/items`): change quantity (`0..ordered`
+    on PO lines) and price (`>= 0`), **delete** a line (it is kept, struck through, excluded from
+    the total, and can be restored), or **add** a catalog item that was not on the PO (no ordered
+    quantity / max). `TotalAmount` is recomputed from the non-deleted lines.
+  - Finalizing applies the agent's edits from the printed copy to the lines (quantity capped
+    between `0` and the ordered quantity, or a line removed) and recomputes `TotalAmount`.
+  - Every change is snapshotted as an `InvoiceVersion` — see
+    [refactor_docs/order_invoice_lifecycle.md](refactor_docs/order_invoice_lifecycle.md#invoice-line-items--version-history).
+  - Frontend, `/sales/orders` row icons: **eye** = invoice preview, **pencil** (Draft) = open the edit page for the
+    draft invoice (`/sales/invoices/[id]/edit`: trash/undo icon per line, add-item row), **printer** (Draft) =
+    mark as printed and open the print tab; on Printed/Finalized the printer reprints without
+    changing status; plus finalize and record payment. `/sales/invoices/[id]` shows the items table
+    (ordered vs billed, Added/Removed badges), the version history, and the same actions.
+  - Invoice document and print tab: see
+    [refactor_docs/order_invoice_lifecycle.md](refactor_docs/order_invoice_lifecycle.md#invoice-screens--printing-frontend).
 - Payments (`payments` API) apply against the invoice, moving `PaymentStatus`:
   `Pending → PartiallyPaid → Paid`.