feat(fusion_accounting_core): add computed coexistence group + recompute hooks

group_fusion_show_when_enterprise_absent has membership = all internal
users iff no Enterprise accounting module is installed. Membership is
recomputed on module install/uninstall via overrides on ir.module.module.
Used by Phase 1 fusion_bank_rec menus to auto-hide when Enterprise is
active and auto-appear after Enterprise uninstall.

Made-with: Cursor

fusion_accounting_core/tests/__init__.py

@@ -1,3 +1,4 @@
 from . import test_enterprise_detection
 from . import test_shared_field_ownership
 from . import test_shared_field_bank_statement
+from . import test_coexistence_group

fusion_accounting_core/tests/test_coexistence_group.py

@@ -0,0 +1,46 @@
+from odoo.tests.common import TransactionCase, tagged
+
+
+@tagged('post_install', '-at_install')
+class TestCoexistenceGroup(TransactionCase):
+    """The 'show when Enterprise absent' group must exist and have computed membership."""
+
+    def test_group_exists(self):
+        group = self.env.ref(
+            'fusion_accounting_core.group_fusion_show_when_enterprise_absent',
+            raise_if_not_found=False,
+        )
+        self.assertTrue(group, "Coexistence group must exist")
+
+    def test_membership_matches_enterprise_state(self):
+        """A user is in the group iff Enterprise accounting is NOT installed.
+
+        We can't toggle Enterprise mid-test, so just assert the current state
+        matches: if Enterprise is installed, group should have 0 members; if
+        not, the group should include all internal users.
+        """
+        group = self.env.ref(
+            'fusion_accounting_core.group_fusion_show_when_enterprise_absent'
+        )
+        enterprise_installed = self.env['ir.module.module']._fusion_is_enterprise_accounting_installed()
+        all_internal = self.env['res.users'].sudo().search([('share', '=', False)])
+        if enterprise_installed:
+            self.assertEqual(
+                len(group.user_ids), 0,
+                "Enterprise installed -> coexistence group should be empty",
+            )
+        else:
+            self.assertEqual(
+                set(group.user_ids.ids), set(all_internal.ids),
+                "Enterprise absent -> coexistence group should contain all internal users",
+            )
+
+    def test_recompute_method_exists(self):
+        """The recompute helper must be callable on res.users."""
+        self.assertTrue(
+            callable(getattr(
+                self.env['res.users'],
+                '_fusion_recompute_coexistence_group',
+                None,
+            ))
+        )