feat(fusion_accounting_assets): asset disposal record model

- 4 disposal types: sale, scrap, donation, lost
- mail.thread tracking on type / date / sale amount / partner
- gain_loss_amount computed:
    - sale: sale_amount - book_value_at_disposal
    - scrap / donation / lost: -book_value_at_disposal (full loss)
- ondelete='restrict' on asset_id (cannot delete an asset with disposal)
- move_id placeholder for engine-created journal entry
- 4 new tests (59 total)

Made-with: Cursor

fusion_accounting_assets/tests/__init__.py

@@ -6,3 +6,4 @@ from . import test_useful_life_predictor
 from . import test_fusion_asset
 from . import test_fusion_asset_depreciation_line
 from . import test_fusion_asset_category
+from . import test_fusion_asset_disposal

fusion_accounting_assets/tests/test_fusion_asset_disposal.py

@@ -0,0 +1,56 @@
+from datetime import date
+
+from odoo.tests.common import TransactionCase
+from odoo.tests import tagged
+
+
+@tagged('post_install', '-at_install')
+class TestFusionAssetDisposal(TransactionCase):
+
+    def setUp(self):
+        super().setUp()
+        self.asset = self.env['fusion.asset'].create({
+            'name': 'Disposable Asset',
+            'cost': 10000,
+            'salvage_value': 0,
+            'acquisition_date': date(2026, 1, 1),
+            'method': 'straight_line',
+            'useful_life_years': 5,
+        })
+
+    def test_create_minimal_sale(self):
+        d = self.env['fusion.asset.disposal'].create({
+            'asset_id': self.asset.id,
+            'disposal_type': 'sale',
+            'sale_amount': 7000,
+            'book_value_at_disposal': 6000,
+        })
+        self.assertEqual(d.gain_loss_amount, 1000)
+        self.assertEqual(d.company_id, self.asset.company_id)
+
+    def test_sale_at_loss(self):
+        d = self.env['fusion.asset.disposal'].create({
+            'asset_id': self.asset.id,
+            'disposal_type': 'sale',
+            'sale_amount': 4000,
+            'book_value_at_disposal': 6000,
+        })
+        self.assertEqual(d.gain_loss_amount, -2000)
+
+    def test_scrap_full_loss(self):
+        d = self.env['fusion.asset.disposal'].create({
+            'asset_id': self.asset.id,
+            'disposal_type': 'scrap',
+            'sale_amount': 0,
+            'book_value_at_disposal': 6000,
+        })
+        self.assertEqual(d.gain_loss_amount, -6000)
+
+    def test_donation_ignores_sale_amount(self):
+        d = self.env['fusion.asset.disposal'].create({
+            'asset_id': self.asset.id,
+            'disposal_type': 'donation',
+            'sale_amount': 999,
+            'book_value_at_disposal': 6000,
+        })
+        self.assertEqual(d.gain_loss_amount, -6000)