feat: add begin repair workflow

backend/app/repairs/__init__.py

@@ -0,0 +1,37 @@
+"""Repair workflow models, persistence, and business services."""
+
+from app.repairs.exceptions import (
+    ActiveRepairConflict,
+    IncompatibleMinerLifecycle,
+    InconsistentRepairState,
+    RepairActorRequired,
+    RepairConflict,
+    RepairError,
+    RepairMinerNotFound,
+    RepairPersistenceError,
+)
+from app.repairs.models import (
+    BeginRepairRequest,
+    BeginRepairResult,
+    RepairReason,
+    RepairStatus,
+)
+from app.repairs.repository import RepairRepository
+from app.repairs.service import RepairService
+
+__all__ = [
+    "ActiveRepairConflict",
+    "BeginRepairRequest",
+    "BeginRepairResult",
+    "IncompatibleMinerLifecycle",
+    "InconsistentRepairState",
+    "RepairActorRequired",
+    "RepairConflict",
+    "RepairError",
+    "RepairMinerNotFound",
+    "RepairPersistenceError",
+    "RepairReason",
+    "RepairRepository",
+    "RepairService",
+    "RepairStatus",
+]