Mutation in generator; category H (stop) scoring and judge; category K variants and tool schema variant; evalset plan

- mutation.py: negation mutants, skip WHILE/DO blocks (endless loop blocked RFC ~8 min)
- generator: accept only after mutation check; survivors go back as repair feedback
- runner/judge.py: stop tasks scored 100/30/0; gap by keywords, else judge model
- proxy: tool schema variant generic_v0 (draft); generator make_k_variant
- evalset.py: 88 slots for step F (A-I, H, K)

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

tasks_gen/eval/G0002/mutation.json

@@ -0,0 +1,59 @@
+{
+ "task": "G0002",
+ "mutants": [
+  {
+   "object": "{{P}}DELIVERY_SCHEDULE",
+   "mutant": "line 68: <> -> = (rel)",
+   "status": "killed",
+   "hidden": "9/12",
+   "failed_tests": [
+    "ADD_DAYS_BACKWARD",
+    "ADD_DAYS_FORWARD",
+    "ADD_FORWARD_SKIPS_HOLIDAY"
+   ]
+  },
+  {
+   "object": "{{P}}DELIVERY_SCHEDULE",
+   "mutant": "line 72: - -> + (arith)",
+   "status": "invalid",
+   "hidden": "0/0",
+   "failed_tests": []
+  },
+  {
+   "object": "{{P}}DELIVERY_SCHEDULE",
+   "mutant": "line 81: = -> <> (eq)",
+   "status": "invalid",
+   "hidden": "0/0",
+   "failed_tests": []
+  },
+  {
+   "object": "{{P}}DELIVERY_SCHEDULE",
+   "mutant": "line 91: 5 -> 6 (const)",
+   "status": "killed",
+   "hidden": "7/12",
+   "failed_tests": [
+    "ADD_DAYS_BACKWARD",
+    "ADD_DAYS_FORWARD",
+    "ADD_FORWARD_SKIPS_HOLIDAY",
+    "NEXT_DAY_FROM_WEEKEND",
+    "WEEKEND_IS_NOT_WORKING"
+   ]
+  },
+  {
+   "object": "{{P}}DELIVERY_SCHEDULE",
+   "mutant": "line 98: abap_true -> abap_false (bool)",
+   "status": "killed",
+   "hidden": "8/12",
+   "failed_tests": [
+    "ADD_FORWARD_SKIPS_HOLIDAY",
+    "COUNT_WORKING_DAYS_INCLUSIVE",
+    "HOLIDAY_IS_NOT_WORKING",
+    "NEXT_DAY_SKIPS_HOLIDAYS"
+   ]
+  }
+ ],
+ "valid": 3,
+ "killed": 3,
+ "kill_rate": 1.0,
+ "ok": true
+}