feat(fusion_accounting_assets): depreciation board line model

- period_index, scheduled_date, amount, accumulated, book_value_at_end
- is_posted / posted_date / move_id (set when engine posts the entry)
- action_post() marks the line as posted (idempotent)
- UNIQUE(asset_id, period_index) constraint via models.Constraint
- 5 new tests (52 total)

Made-with: Cursor

fusion_accounting_assets/tests/__init__.py

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

fusion_accounting_assets/tests/test_fusion_asset_depreciation_line.py

@@ -0,0 +1,62 @@
+from datetime import date
+
+from odoo.tests.common import TransactionCase
+from odoo.tests import tagged
+
+
+@tagged('post_install', '-at_install')
+class TestFusionAssetDepreciationLine(TransactionCase):
+
+    def setUp(self):
+        super().setUp()
+        self.asset = self.env['fusion.asset'].create({
+            'name': 'Asset for Lines',
+            'cost': 12000,
+            'salvage_value': 0,
+            'acquisition_date': date(2026, 1, 1),
+            'method': 'straight_line',
+            'useful_life_years': 1,
+        })
+
+    def _make_line(self, period_index, amount=1000.0, scheduled_date=None):
+        return self.env['fusion.asset.depreciation.line'].create({
+            'asset_id': self.asset.id,
+            'period_index': period_index,
+            'scheduled_date': scheduled_date or date(2026, period_index, 28),
+            'amount': amount,
+        })
+
+    def test_create_line_defaults_unposted(self):
+        line = self._make_line(1)
+        self.assertFalse(line.is_posted)
+        self.assertFalse(line.posted_date)
+        self.assertFalse(line.move_id)
+        self.assertEqual(line.company_id, self.asset.company_id)
+        self.assertEqual(line.currency_id, self.asset.currency_id)
+
+    def test_action_post_marks_line_posted(self):
+        line = self._make_line(2)
+        line.action_post()
+        self.assertTrue(line.is_posted)
+        self.assertTrue(line.posted_date)
+
+    def test_action_post_idempotent_keeps_first_date(self):
+        line = self._make_line(3)
+        line.action_post()
+        first_date = line.posted_date
+        line.action_post()
+        self.assertEqual(line.posted_date, first_date)
+
+    def test_unique_period_per_asset(self):
+        self._make_line(4)
+        with self.assertRaises(Exception):
+            self._make_line(4)
+
+    def test_book_value_reflects_posted_lines_only(self):
+        l1 = self._make_line(5, amount=1000)
+        self._make_line(6, amount=1500)
+        self.assertEqual(self.asset.book_value, 12000)
+        l1.action_post()
+        self.asset.invalidate_recordset(['book_value', 'total_depreciated'])
+        self.assertEqual(self.asset.total_depreciated, 1000)
+        self.assertEqual(self.asset.book_value, 11000)