feat(fusion_accounting_assets): asset category template model

- defaults applied to new assets (method, useful_life, declining rate,
  salvage %, prorate convention)
- GL account hooks: asset_account_id, depreciation_account_id,
  expense_account_id (domain-filtered to relevant account types)
- computed asset_count for kanban / list views
- 3 new tests (55 total)

Made-with: Cursor

fusion_accounting_assets/tests/__init__.py

@@ -5,3 +5,4 @@ from . import test_asset_anomaly_detection
 from . import test_useful_life_predictor
 from . import test_fusion_asset
 from . import test_fusion_asset_depreciation_line
+from . import test_fusion_asset_category

fusion_accounting_assets/tests/test_fusion_asset_category.py

@@ -0,0 +1,35 @@
+from datetime import date
+
+from odoo.tests.common import TransactionCase
+from odoo.tests import tagged
+
+
+@tagged('post_install', '-at_install')
+class TestFusionAssetCategory(TransactionCase):
+
+    def test_create_with_defaults(self):
+        cat = self.env['fusion.asset.category'].create({'name': 'Computers'})
+        self.assertEqual(cat.method, 'straight_line')
+        self.assertEqual(cat.useful_life_years, 5)
+        self.assertEqual(cat.prorate_convention, 'days_period')
+        self.assertEqual(cat.asset_count, 0)
+
+    def test_asset_count_reflects_linked_assets(self):
+        cat = self.env['fusion.asset.category'].create({'name': 'Vehicles'})
+        for i in range(3):
+            self.env['fusion.asset'].create({
+                'name': f'Truck {i}',
+                'cost': 50000,
+                'acquisition_date': date(2026, 1, 1),
+                'method': 'declining_balance',
+                'category_id': cat.id,
+            })
+        cat.invalidate_recordset(['asset_count'])
+        self.assertEqual(cat.asset_count, 3)
+
+    def test_method_must_be_in_selection(self):
+        with self.assertRaises(Exception):
+            self.env['fusion.asset.category'].create({
+                'name': 'Bogus',
+                'method': 'not_a_method',
+            })