feat: add custom stickers

lib/api.ts

@@ -451,6 +451,21 @@ export type GiftableReward = {
 export const rewardGifts = {
   catalog: () => call<GiftableReward[]>("/admin/reward-gifts/catalog").then((r) => r.data),
 
+  /** Presign artwork for a custom gift. Returns the final public URL too,
+   *  since sadhna_rewards.image_url stores an absolute address. */
+  presignImage: (contentType: string) =>
+    call<{ upload_url: string; image_url: string }>(
+      "/admin/reward-gifts/image-presign",
+      { method: "POST", body: JSON.stringify({ content_type: contentType }) },
+    ).then((r) => r.data),
+
+  /** Add a sticker to the catalog. It reaches nobody until it is sent. */
+  create: (input: { name: string; meaning: string; image_url: string }) =>
+    call<GiftableReward>("/admin/reward-gifts/catalog", {
+      method: "POST",
+      body: JSON.stringify(input),
+    }).then((r) => r.data),
+
   /** Hand a reward to every account, unopened. Idempotent — a repeat only
    *  reaches people who don't already have it. */
   send: (rewardKey: string) =>