feat: add manual 'verify & fix all interactions' admin tool

New POST /api/admin/import/furni/verify re-runs the full interaction
verification over items_base at any time, plus a Tools dropdown entry
in the furni import admin. It corrects interaction_type,
interaction_modes_count and allow_sit/lay/walk against real furniture
data (furnidata flags + .nitro animation states); items without real
data are skipped and existing emulator handler types are preserved.

src/app/api/admin/import/furni/verify/route.ts

@@ -0,0 +1,18 @@
+import { withAdmin } from "@/lib/api-handler";
+import { apiOk } from "@/lib/api-response";
+import { PERMS } from "@/lib/permissions";
+import { verifyAndFixInteractionModesCount } from "@/lib/services/furni-import";
+
+/**
+ * POST /api/admin/import/furni/verify
+ *
+ * Re-runs the interaction verification over the ENTIRE items_base table,
+ * correcting interaction_type, interaction_modes_count and allow_sit/
+ * allow_lay/allow_walk against the real furniture data (furnidata flags +
+ * .nitro animation states). Only items with authoritative data are touched —
+ * no keyword guesses, so no false positives.
+ */
+export const POST = withAdmin({ permission: PERMS.ASSETS_IMPORT }, async () => {
+	const result = await verifyAndFixInteractionModesCount();
+	return apiOk(result);
+});

src/lib/admin/verify-interactions.ts

@@ -0,0 +1,40 @@
+export const VERIFY_INTERACTIONS_URL = "/api/admin/import/furni/verify";
+
+export interface VerifyInteractionsResult {
+	fixed: number;
+	checked: number;
+	skipped: number;
+	errors: string[];
+}
+
+type AdminFetcher = (
+	input: RequestInfo | URL,
+	init?: RequestInit,
+) => Promise<Response>;
+
+export async function requestVerifyInteractions(
+	fetcher: AdminFetcher,
+): Promise<VerifyInteractionsResult> {
+	const response = await fetcher(VERIFY_INTERACTIONS_URL, { method: "POST" });
+	const payload = (await response.json()) as Record<string, unknown>;
+	if (!response.ok) {
+		throw new Error(
+			typeof payload.error === "string"
+				? payload.error
+				: "Interaction verification failed",
+		);
+	}
+
+	const errors = Array.isArray(payload.errors)
+		? payload.errors.filter(
+				(value): value is string => typeof value === "string",
+			)
+		: [];
+
+	return {
+		fixed: Number(payload.fixed) || 0,
+		checked: Number(payload.checked) || 0,
+		skipped: Number(payload.skipped) || 0,
+		errors,
+	};
+}