Snapshot: new training tasks (balanced generation), docs

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

tasks_gen/train/G1944/mutation.json

@@ -0,0 +1,40 @@
+{
+ "task": "G1944",
+ "mutants": [
+  {
+   "object": "{{P}}SHARP_SUM",
+   "mutant": "line 30: * -> / (arith)",
+   "status": "invalid",
+   "hidden": "0/0",
+   "failed_tests": []
+  },
+  {
+   "object": "{{P}}SHARP_SUM",
+   "mutant": "line 33: >= -> < (rel)",
+   "status": "killed",
+   "hidden": "1/6",
+   "failed_tests": [
+    "ALL_CUSTOMERS",
+    "CUSTOMER_FILTER",
+    "FEE_AND_KNIVES",
+    "SORTED_BY_FEE",
+    "UNKNOWN_TYPE"
+   ]
+  },
+  {
+   "object": "{{P}}SHARP_SUM",
+   "mutant": "line 34: AND -> OR (logic)",
+   "status": "killed",
+   "hidden": "3/6",
+   "failed_tests": [
+    "CUSTOMER_FILTER",
+    "DATE_FILTER",
+    "UNKNOWN_TYPE"
+   ]
+  }
+ ],
+ "valid": 2,
+ "killed": 2,
+ "kill_rate": 1.0,
+ "ok": true
+}