Name normalization and dedupe

Add harness.Normalize (lowercase, fold accents, strip punctuation, drop
filler words, collapse whitespace), harness.Similar (token-set Jaccard
similarity, threshold 0.85) and a Deduper built from the Regulars, Quest
log, pending suggestions and passed names that answers IsDuplicate.

Maestro task: f046ec6c-dbe2-4b12-bc95-3081c07714eb

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/ARCHITECTURE.md

@@ -164,6 +164,13 @@ automatic** (D-021).
   last 60 passed Side quests and the plans of the last four ISO weeks. A
   character budget trims the oldest plans first, then the oldest passes;
   Regulars and the Quest log are never trimmed.
+- **Name dedupe** (`harness.Normalize`, `harness.Similar`, `harness.Deduper`):
+  a dinner name is normalized by lowercasing, folding accents, stripping
+  punctuation, dropping filler words (easy, best, homemade, quick, simple,
+  the, a, recipe, classic) and collapsing whitespace. Two names are the same
+  dinner when the token-set (Jaccard) similarity of their words is at least
+  0.85. A `Deduper` over the Regulars, Quest log, pending suggestions and
+  passed names rejects a suggestion that repeats any of them.
 
 ## Recipe grounding