feat(fusion_accounting_followup): AI follow-up text generator + prompt

Made-with: Cursor

fusion_accounting_followup/tests/__init__.py

@@ -2,3 +2,4 @@ from . import test_overdue_aging
 from . import test_level_resolver
 from . import test_risk_scorer
 from . import test_tone_selector
+from . import test_followup_text_generator