refactor(fusion_accounting_ai): route accounts_receivable tools through FollowupAdapter

Task 13 Step 7 of phase-0 plan.

Routes the AR tools through the FollowupAdapter so they work identically on
fusion-native, Enterprise, and pure Community installs:

  - get_ar_aging → FollowupAdapter.aged_receivables()
  - get_overdue_invoices → FollowupAdapter.overdue_invoices()
  - send_followup → FollowupAdapter.send_followup()
  - get_followup_report → FollowupAdapter.followup_report_html()

FollowupAdapter extended:

  - overdue_invoices() now includes partner_email, partner_phone and
    amount_total so the tool wrapper can render its richer response.
  - aged_receivables() and aged_payables() new shared-implementation method
    _aged_buckets() produces the 5-bucket aging shape the AR/AP tools emit.
  - followup_report_html() and send_followup() isolate the Enterprise
    account.followup.report / partner.execute_followup calls; Community mode
    returns a graceful error dict.

Pure-Community tools in accounts_receivable.py (get_partner_balance,
reconcile_payment_to_invoice, get_unmatched_payments) unchanged — they touch
account.move / account.move.line directly which is tri-mode safe.

3 new data-adapter tests added (total: 9; all passing on westin-v19).

Made-with: Cursor

fusion_accounting_ai/tests/test_data_adapters.py

@@ -83,6 +83,38 @@ class TestFollowupAdapter(TransactionCase):
         rows = adapter.overdue_invoices(days_overdue=30)
         self.assertIsInstance(rows, list)
 
+    def test_overdue_invoices_row_has_contact_fields(self):
+        """The enriched shape must include email, phone, and amount_total so
+        the accounts_receivable tool wrapper can render them."""
+        adapter = get_adapter(self.env, 'followup')
+        rows = adapter.overdue_invoices(days_overdue=30, limit=5)
+        for row in rows:
+            for key in (
+                'id', 'name', 'partner_id', 'partner_name',
+                'partner_email', 'partner_phone',
+                'invoice_date_due', 'amount_total', 'amount_residual',
+                'days_overdue',
+            ):
+                self.assertIn(key, row, f"Missing key {key!r} in overdue row")
+
+    def test_aged_receivables_returns_bucket_shape(self):
+        adapter = get_adapter(self.env, 'followup')
+        result = adapter.aged_receivables(company_id=self.env.company.id)
+        self.assertIn('total', result)
+        self.assertIn('buckets', result)
+        self.assertIn('line_count', result)
+        for bucket in ('current', '1_30', '31_60', '61_90', '90_plus'):
+            self.assertIn(bucket, result['buckets'])
+
+    def test_aged_payables_returns_bucket_shape(self):
+        adapter = get_adapter(self.env, 'followup')
+        result = adapter.aged_payables(company_id=self.env.company.id)
+        self.assertIn('total', result)
+        self.assertIn('buckets', result)
+        self.assertIn('line_count', result)
+        for bucket in ('current', '1_30', '31_60', '61_90', '90_plus'):
+            self.assertIn(bucket, result['buckets'])
+
 
 @tagged('post_install', '-at_install')
 class TestAssetsAdapter(TransactionCase):