content: tree-wide block transforms (transform.sx) + 12 tests (586/586)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/content/scoreboard.json

@@ -14,6 +14,7 @@
     "tree-edit": {"pass": 17, "fail": 0},
     "clone": {"pass": 10, "fail": 0},
     "query": {"pass": 13, "fail": 0},
+    "transform": {"pass": 12, "fail": 0},
     "stats": {"pass": 17, "fail": 0},
     "table": {"pass": 15, "fail": 0},
     "data": {"pass": 21, "fail": 0},
@@ -28,7 +29,7 @@
     "md-doc": {"pass": 12, "fail": 0},
     "fed": {"pass": 20, "fail": 0}
   },
-  "total_pass": 574,
+  "total_pass": 586,
   "total_fail": 0,
-  "total": 574
+  "total": 586
 }