feat: migrate setup visibility from boolean to three-tier system

Replace isPublic boolean with visibility enum (private/link/public) across
the full stack. Add shares table to schema for future share link support.
Update all services, routes, schemas, hooks, components, and tests.

Plan: 32-01 (Setup Sharing System - Schema Migration)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/client/components/SetupCard.tsx

@@ -4,7 +4,7 @@ import { useFormatters } from "../hooks/useFormatters";
 interface SetupCardProps {
 	id: number;
 	name: string;
-	isPublic?: boolean;
+	visibility?: "private" | "link" | "public";
 	itemCount: number;
 	totalWeight: number;
 	totalCost: number;
@@ -13,7 +13,7 @@ interface SetupCardProps {
 export function SetupCard({
 	id,
 	name,
-	isPublic,
+	visibility,
 	itemCount,
 	totalWeight,
 	totalCost,
@@ -30,9 +30,15 @@ export function SetupCard({
 					<h3 className="text-sm font-semibold text-gray-900 truncate">
 						{name}
 					</h3>
-					{isPublic && (
-						<span className="inline-flex items-center px-1.5 py-0.5 rounded-full text-[10px] font-medium bg-green-50 text-green-600 shrink-0">
-							Public
+					{visibility && visibility !== "private" && (
+						<span
+							className={`inline-flex items-center px-1.5 py-0.5 rounded-full text-[10px] font-medium shrink-0 ${
+								visibility === "public"
+									? "bg-green-50 text-green-600"
+									: "bg-blue-50 text-blue-600"
+							}`}
+						>
+							{visibility === "public" ? "Public" : "Link"}
 						</span>
 					)}
 				</div>