content: find-replace rewrites all text-bearing fields (756/756)

fr-rewrite dispatches per block type so image alt, list items, and table
headers/cells are renamed alongside text/heading/code/quote/callout —
matching exactly the set asText/stats/word-count fold into prose. Prior
find-replace skipped them, so a rename stayed visible in counts/exports.

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

lib/content/scoreboard.json

@@ -21,7 +21,7 @@
     "flatten": {"pass": 10, "fail": 0},
     "transform": {"pass": 12, "fail": 0},
     "normalize": {"pass": 11, "fail": 0},
-    "find-replace": {"pass": 12, "fail": 0},
+    "find-replace": {"pass": 16, "fail": 0},
     "stats": {"pass": 17, "fail": 0},
     "summary": {"pass": 14, "fail": 0},
     "index": {"pass": 13, "fail": 0},
@@ -42,7 +42,7 @@
     "md-doc": {"pass": 12, "fail": 0},
     "fed": {"pass": 20, "fail": 0}
   },
-  "total_pass": 752,
+  "total_pass": 756,
   "total_fail": 0,
-  "total": 752
+  "total": 756
 }