Phase 13.19.GB-PERF: update CAPABILITY_MATRIX snapshot

Auto-generated from run_tests.sh at commit 180bf20.
0 broken / 0 partial / 43 verified / 133 total.
Note: phase label in header still reads 13.14.GB (cosmetic
run_tests.sh template issue, not a data issue).

Author: miranov25

UTILS/dfextensions/groupby_regression/docs/CAPABILITY_MATRIX.md

@@ -1,6 +1,6 @@
 # Capability Matrix — groupby_regression
 
-**Generated:** 2026-04-11 07:03 UTC
+**Generated:** 2026-04-18 12:12 UTC
 **Phase:** Phase 13.14.GB
 **Generator:** `scripts/generate_capability_matrix.py`