feat(approval): add task workflow and waiver decisions

server/src/app/models/__init__.py

@@ -12,6 +12,7 @@ from app.models.ai_learning import AIDecision, AIDecisionFeedback, WorkflowOutco
 from app.models.ai_memory import MemoryEntry, MemoryEvidenceLink
 from app.models.approval import ApprovalRecord
 from app.models.approval_action import ApprovalActionLedger
+from app.models.approval_task import ApprovalTask, ApprovalTaskEvent
 from app.models.attachment_association_job import AttachmentAssociationJob
 from app.models.audit_log import AuditLog
 from app.models.auth_session import AuthSession
@@ -57,6 +58,8 @@ __all__ = [
     "AIApplicationPreviewDecision",
     "ApprovalRecord",
     "ApprovalActionLedger",
+    "ApprovalTask",
+    "ApprovalTaskEvent",
     "AttachmentAssociationJob",
     "AuditLog",
     "AuthSession",