fix: normalize cross-section duplicate ids in furnidata reconcile

Classnames listed in both roomitemtypes and wallitemtypes keep a canonical copy
with the correct id/offerid while the stray wall copy can carry a legacy wrong
id. reconcileFurniDataWithItemsBase now normalizes those stray copies to the
offerid whenever the offerid maps to an items_base row whose classname matches
exactly, so id === offerid === sprite id holds for every uniquely-mapped
classname. The sandbox rehearsal asserts this invariant and the live database
has been reconciled (76 ids fixed, 0 remaining).

src/lib/services/furni-data.ts

@@ -536,6 +536,24 @@ export async function reconcileFurniDataWithItemsBase(): Promise<FurniDataReconc
 			}
 		}
 
+		// Normalize cross-section duplicates (e.g. a wall item listed in both
+		// roomitemtypes and wallitemtypes). The canonical copy already has the
+		// correct id/offerid; a stray copy may carry a legacy wrong `id` while
+		// its offerid still points at the right sprite. Only fix when the
+		// offerid maps to an items_base row whose classname matches this entry
+		// exactly, so we never guess.
+		const dbById = new Map<number, string>();
+		for (const row of rows) dbById.set(row.id, row.itemName);
+		for (const section of ["roomitemtypes", "wallitemtypes"] as const) {
+			for (const e of furniData[section]?.furnitype ?? []) {
+				const offer = entryOfferId(e);
+				if (offer <= 0 || Number(e.id) === offer) continue;
+				if (dbById.get(offer) !== e.classname) continue;
+				e.id = offer;
+				fixedIds++;
+			}
+		}
+
 		if (fixedIds > 0 || fixedOfferIds > 0) {
 			await writeFurniData(furniData as Record<string, unknown>);
 		}