test(benchmarks): tag tasks as small change, larger implementation, or search

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/benchmarks/tasks/03-delegation-parsers/task.json

@@ -1,4 +1,5 @@
 {
+  "category": "larger implementation",
   "prompt": "Implement the three independent parsers in app/parsers (csv_parser, json_parser, ini_parser) according to their docstrings, and add unit tests for each. They share no code.",
   "workflow": {
     "kind": "larger change with justified delegation",