Mutation check done on all accepted tasks; mutant fixes; dump filter in proxy

- skip sy-subrc lines and CDS type lengths; CDS literal mutants; mutate helper classes
- proxy: sap_short_dumps shows only dumps of the current run
- 26/26 tasks pass; results in docs/faz1-tasarim.md 11g

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014aUaQeLnwbb1zTpN7kHeat

tasks_gen/eval/G0020/mutation.json

@@ -0,0 +1,56 @@
+{
+ "task": "G0020",
+ "mutants": [
+  {
+   "object": "{{P}}I_BOOK_REVENUE",
+   "mutant": "line 8: inner join -> left outer join (join)",
+   "status": "survived",
+   "hidden": "8/8",
+   "failed_tests": []
+  },
+  {
+   "object": "{{P}}I_BOOK_REVENUE",
+   "mutant": "line 8: = -> <> (eq)",
+   "status": "killed",
+   "hidden": "2/8",
+   "failed_tests": [
+    "BOOKS_IN_PERIOD",
+    "BOOK_OUTSIDE_PERIOD_HIDDEN",
+    "PERIOD_LIMITS_INCLUDED",
+    "REVENUE_HAS_TWO_DECIMALS",
+    "REVENUE_IN_PERIOD",
+    "SOLD_QUANTITY_IN_PERIOD"
+   ]
+  },
+  {
+   "object": "{{P}}I_BOOK_REVENUE",
+   "mutant": "line 13: sum( -> max( (agg)",
+   "status": "killed",
+   "hidden": "7/8",
+   "failed_tests": [
+    "SOLD_QUANTITY_IN_PERIOD"
+   ]
+  },
+  {
+   "object": "{{P}}I_BOOK_REVENUE",
+   "mutant": "line 14: sum( -> max( (agg)",
+   "status": "killed",
+   "hidden": "6/8",
+   "failed_tests": [
+    "REVENUE_HAS_TWO_DECIMALS",
+    "REVENUE_IN_PERIOD"
+   ]
+  },
+  {
+   "object": "{{P}}I_BOOK_REVENUE",
+   "mutant": "line 16: and -> or (logic)",
+   "status": "invalid",
+   "hidden": "0/0",
+   "failed_tests": []
+  }
+ ],
+ "valid": 4,
+ "killed": 3,
+ "kill_rate": 0.75,
+ "ok": true
+}