Pipeline controller: plan 2 (hard +, error +50 %), backlog throttle, 2 trajectory workers, stop rules, summaries every 50; budget reserve

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

tasks_gen/train/G1028/mutation.json

@@ -0,0 +1,39 @@
+{
+ "task": "T20",
+ "mutants": [
+  {
+   "object": "{{P}}I_DEPT",
+   "mutant": "line 5: association on: $projection.parent_id -> $projection.dept_id (assoc on)",
+   "status": "killed",
+   "hidden": "3/6",
+   "failed_tests": [
+    "ORPHAN_HAS_NO_PARENT",
+    "PARENT_NAME",
+    "TOP_HAS_NO_PARENT"
+   ]
+  },
+  {
+   "object": "{{P}}I_DEPT",
+   "mutant": "line 10: headcount -> dept_id (element)",
+   "status": "killed",
+   "hidden": "5/6",
+   "failed_tests": [
+    "HEADCOUNT_SHOWN"
+   ]
+  },
+  {
+   "object": "{{P}}I_DEPT",
+   "mutant": "line 8: dept_name -> dept_id (element)",
+   "status": "killed",
+   "hidden": "4/6",
+   "failed_tests": [
+    "OWN_DATA_SHOWN",
+    "PARENT_NAME"
+   ]
+  }
+ ],
+ "valid": 3,
+ "killed": 3,
+ "kill_rate": 1.0,
+ "ok": true
+}