fix(payments): point manage subscription to org customer portal

ui/src/routes/profile/+page.svelte

@@ -13,11 +13,8 @@
 	const emailParam = data.email ? `?customer_email=${encodeURIComponent(data.email)}` : '';
 	const checkoutMonthly = `https://buy.polar.sh/polar_cl_KtOHiuL2UkiQ4hrojBfINnxlCTORX1A8DeUUO18irVA${emailParam}`;
 	const checkoutAnnual  = `https://buy.polar.sh/polar_cl_ylmUnsorSBCgNMhWVG7iO8zVQBnr5cVeLJlW74fm5kG${emailParam}`;
-	// Customer portal: if user already has a Polar customer ID, link to their portal;
-	// otherwise fall back to the org page
-	const manageUrl = data.polarCustomerId
-		? `https://polar.sh/purchases`
-		: `https://polar.sh/libnovel`;
+	// Customer portal: always link to the org portal — customer logs in with checkout email
+	const manageUrl = `https://polar.sh/libnovel/portal`;
 
 	// ── Avatar ───────────────────────────────────────────────────────────────────
 	let avatarUrl = $state<string | null>(untrack(() => data.avatarUrl ?? null));