content: global find/replace (find-replace.sx) + 10 tests (615/615)

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

lib/content/scoreboard.json

@@ -17,6 +17,7 @@
     "toc": {"pass": 8, "fail": 0},
     "transform": {"pass": 12, "fail": 0},
     "normalize": {"pass": 11, "fail": 0},
+    "find-replace": {"pass": 10, "fail": 0},
     "stats": {"pass": 17, "fail": 0},
     "table": {"pass": 15, "fail": 0},
     "data": {"pass": 21, "fail": 0},
@@ -31,7 +32,7 @@
     "md-doc": {"pass": 12, "fail": 0},
     "fed": {"pass": 20, "fail": 0}
   },
-  "total_pass": 605,
+  "total_pass": 615,
   "total_fail": 0,
-  "total": 605
+  "total": 615
 }