refactor(fusion_accounting): move security groups to _core, add multi-company session rule

Made-with: Cursor

fusion_accounting_core/migrations/19.0.1.0.0/post-migration.py

@@ -0,0 +1,48 @@
+"""Reassign security group/category/privilege xml-ids from the old module name.
+
+Pre-Phase-0, the three fusion security groups (user, manager, admin), the
+module category and the privilege all lived in module='fusion_accounting'.
+Post-Phase-0 (Task 16) they moved into module='fusion_accounting_core'.
+
+Odoo loads the XML from the new location on upgrade, but the existing
+ir_model_data rows still reference the old module. This script rewrites them.
+
+Both fusion_accounting_core and fusion_accounting_ai ship an equivalent
+UPDATE — whichever post-migration runs first wins the rehoming, the other
+is a no-op. This redundancy protects the common case where the two modules
+are upgraded in either order (as well as the case where only one is
+installed in a given database).
+
+Idempotent: running it a second time matches zero rows.
+"""
+
+import logging
+
+_logger = logging.getLogger(__name__)
+
+
+CORE_SECURITY_NAMES = (
+    'module_category_fusion_accounting',
+    'res_groups_privilege_fusion_accounting',
+    'group_fusion_accounting_user',
+    'group_fusion_accounting_manager',
+    'group_fusion_accounting_admin',
+)
+
+
+def migrate(cr, version):
+    cr.execute(
+        """
+        UPDATE ir_model_data
+        SET module = 'fusion_accounting_core'
+        WHERE module = 'fusion_accounting'
+          AND name = ANY(%s)
+        """,
+        (list(CORE_SECURITY_NAMES),),
+    )
+    moved = cr.rowcount
+    _logger.info(
+        "fusion_accounting_core post-migration: reassigned %d security rows "
+        "from module='fusion_accounting' to module='fusion_accounting_core'",
+        moved,
+    )