feat(fusion_accounting_ai): add ReportsAdapter with trial_balance

Made-with: Cursor

fusion_accounting_ai/tests/test_data_adapters.py

@@ -58,3 +58,19 @@ class TestBankRecAdapter(TransactionCase):
         ids = [r['id'] for r in rows]
         self.assertIn(self.line.id, ids,
             f"Expected line {self.line.id} in unreconciled list, got: {ids}")
+
+
+@tagged('post_install', '-at_install')
+class TestReportsAdapter(TransactionCase):
+    """Verify the reports adapter computes a trial-balance-shaped result."""
+
+    def test_trial_balance_returns_rows_in_pure_community(self):
+        adapter = get_adapter(self.env, 'reports')
+        # Compute an empty-filter trial balance for the current company. Should
+        # return a list (possibly empty in a fresh test DB) without errors.
+        result = adapter.trial_balance()
+        self.assertIsInstance(result, list)
+        # Each row should have account_id and balance keys
+        for row in result:
+            self.assertIn('account_id', row)
+            self.assertIn('balance', row)