feat: add return to service workflow

backend/app/identity.py

@@ -682,11 +682,22 @@ def repair_timeline_request(path: str) -> bool:
     )
 
 
+def repair_completion_request(path: str) -> bool:
+    parts = path.split("/")
+    return (
+        len(parts) == 5
+        and parts[:3] == ["", "api", "repairs"]
+        and parts[4] == "complete"
+    )
+
+
 def required_api_permission(method: str, path: str) -> str | None:
     if path.startswith("/api/admin/"):
         return "users.manage"
     if method == "POST" and path == "/api/repairs":
         return "repairs.create"
+    if method == "POST" and repair_completion_request(path):
+        return "repairs.complete"
     if method == "GET" and repair_timeline_request(path):
         return "repairs.read"
     if method == "GET":