fix: shop catalog always reflects latest data after admin changes

- Add force-dynamic to /api/catalog so Next.js never serves a
  stale cached route response to the shop
- Add invalidateCatalogCache() to catalog-cache lib to drop the
  30s in-process memory cache on demand
- Call invalidateCatalogCache() after every admin PATCH/DELETE on
  an item so override saves are reflected on the very next shop
  request (no 30s delay)

Refresh from Square already updated the shared disk + memory cache;
force-dynamic ensures the shop route handler actually runs each time.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

estore/src/app/api/admin/items/[id]/route.ts

@@ -1,5 +1,6 @@
 import { NextResponse } from 'next/server'
 import { setOverride, clearOverride } from '@/lib/overrides'
+import { invalidateCatalogCache } from '@/lib/catalog-cache'
 import type { ItemOverride } from '@/lib/overrides'
 
 export async function PATCH(
@@ -9,6 +10,7 @@ export async function PATCH(
   try {
     const patch: Partial<ItemOverride> = await request.json()
     setOverride(params.id, patch)
+    invalidateCatalogCache()   // shop picks up override changes on next request
     return NextResponse.json({ ok: true })
   } catch (err) {
     console.error('[admin/items/patch] error:', err)
@@ -23,6 +25,7 @@ export async function DELETE(
 ) {
   try {
     clearOverride(params.id)
+    invalidateCatalogCache()   // shop picks up reset on next request
     return NextResponse.json({ ok: true })
   } catch (err) {
     console.error('[admin/items/delete] error:', err)

estore/src/app/api/catalog/route.ts

@@ -3,6 +3,8 @@ import { getCatalog } from '@/lib/catalog-cache'
 import { readOverrides } from '@/lib/overrides'
 import type { CatalogItem } from '@/data/mock-catalog'
 
+export const dynamic = 'force-dynamic'
+
 function applyOverrides(items: CatalogItem[]): CatalogItem[] {
   const overrides = readOverrides()
 

estore/src/lib/catalog-cache.ts

@@ -53,6 +53,12 @@ export async function refreshCatalog(): Promise<{ items: CatalogItem[]; fetchedA
   return { items, fetchedAt: new Date() }
 }
 
+/** Drop the in-process memory cache so the next request re-reads from disk.
+ *  Call this after writing overrides so the shop picks up changes immediately. */
+export function invalidateCatalogCache(): void {
+  memCache = null
+}
+
 // ── Get (from cache or fetch) ─────────────────────────────────────────────────
 
 export async function getCatalog(): Promise<{ items: CatalogItem[]; fetchedAt: Date | null }> {