Improved static upgrade flow (#5214)

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frontend/src/proprietary/utils/planTierUtils.ts

@@ -0,0 +1,40 @@
+/**
+ * Shared utilities for plan tier comparisons and button logic
+ */
+
+export type PlanTier = 'free' | 'server' | 'enterprise';
+
+const TIER_HIERARCHY: Record<PlanTier, number> = {
+  'free': 1,
+  'server': 2,
+  'enterprise': 3,
+};
+
+/**
+ * Get numeric level for a tier
+ */
+export function getTierLevel(tier: PlanTier | string | null | undefined): number {
+  if (!tier) return 1;
+  return TIER_HIERARCHY[tier as PlanTier] || 1;
+}
+
+/**
+ * Check if target tier is the current tier
+ */
+export function isCurrentTier(currentTier: PlanTier | string | null | undefined, targetTier: PlanTier | string): boolean {
+  return getTierLevel(currentTier) === getTierLevel(targetTier);
+}
+
+/**
+ * Check if target tier is a downgrade from current tier
+ */
+export function isDowngrade(currentTier: PlanTier | string | null | undefined, targetTier: PlanTier | string): boolean {
+  return getTierLevel(currentTier) > getTierLevel(targetTier);
+}
+
+/**
+ * Check if enterprise is blocked for free tier users
+ */
+export function isEnterpriseBlockedForFree(currentTier: PlanTier | string | null | undefined, targetTier: PlanTier | string): boolean {
+  return currentTier === 'free' && targetTier === 'enterprise';
+}