search: fuzzy matching via edit distance + 18 tests

editDist as an O(m*n) row-based Levenshtein DP (naive recursion is exponential
and times out under load); fuzzyTerms/fuzzyDocs/fuzzyRankTfIdf expand a term to
indexed terms within a max edit distance. 166/166.

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

lib/search/scoreboard.json

@@ -1,8 +1,8 @@
 {
   "lang": "search",
-  "total_passed": 148,
+  "total_passed": 166,
   "total_failed": 0,
-  "total": 148,
+  "total": 166,
   "suites": [
     {"name":"index","passed":18,"failed":0,"total":18},
     {"name":"boolean","passed":28,"failed":0,"total":28},
@@ -10,7 +10,8 @@
     {"name":"rank","passed":23,"failed":0,"total":23},
     {"name":"integration","passed":21,"failed":0,"total":21},
     {"name":"prefix","passed":14,"failed":0,"total":14},
-    {"name":"page","passed":12,"failed":0,"total":12}
+    {"name":"page","passed":12,"failed":0,"total":12},
+    {"name":"fuzzy","passed":18,"failed":0,"total":18}
   ],
-  "generated": "2026-06-06T20:54:50+00:00"
+  "generated": "2026-06-06T21:47:28+00:00"
 }