[18.0][IMP] account_reconcile_oca: onchange manual_partner_id

Manual partner change on liquidity line updates other lines and ensures the consistent partner across all displayed reconcile lines (like in enterprise).
Updating partner on other lines does not propagate.

Author: Qlasta

account_reconcile_oca/models/account_bank_statement_line.py

@@ -508,6 +508,7 @@ def _onchange_manual_reconcile_vals(self):
                 in_currency_date,
             )
         self.previous_manual_amount_in_currency = self.manual_amount_in_currency
+        edited_is_liquidity = False
         for line in data:
             if line["reference"] == self.manual_reference:
                 if self._check_line_changed(line):
@@ -516,7 +517,8 @@ def _onchange_manual_reconcile_vals(self):
                         line["kind"] if line["kind"] != "suspense" else "other"
                     )
                     line.update(line_vals)
-                    if line["kind"] == "liquidity":
+                    edited_is_liquidity = line.get("kind") == "liquidity"
+                    if edited_is_liquidity:
                         self._update_move_partner()
             if self.manual_line_id and self.manual_line_id.id == line.get(
                 "original_exchange_line_id"
@@ -544,6 +546,30 @@ def _onchange_manual_reconcile_vals(self):
         )
         self.can_reconcile = self.reconcile_data_info.get("can_reconcile", False)
 
+        # Ensure the UI shows consistent partner across all displayed lines:
+        # only when editing liquidity line
+        if not edited_is_liquidity:
+            return
+        partner_value = (
+            [self.manual_partner_id.id, self.manual_partner_id.display_name]
+            if self.manual_partner_id
+            else False
+        )
+        info = dict(self.reconcile_data_info or {})
+        reconcile_lines = list(info.get("data") or [])
+        if not reconcile_lines:
+            self.reconcile_data_info = info
+            return
+        updated_lines = []
+        for line in reconcile_lines:
+            new_line = dict(line)
+            # Update only the "other" displayed line(s)
+            if new_line.get("kind") != "liquidity":
+                new_line["partner_id"] = partner_value
+            updated_lines.append(new_line)
+        info["data"] = updated_lines
+        self.reconcile_data_info = info
+
     def _update_move_partner(self):
         if self.partner_id == self.manual_partner_id:
             return