Restore subscriptions in store and account modal (#4461)

Reverts cdcc7747 ("Hide subscriptions in store and account modal behind
a feature flag").

This re-adds the Subscriptions tab to the store, restores the
subscription panel on the account modal, and re-enables the cosmetics
fetch — removing the `SUBSCRIPTIONS_ENABLED` feature flag that gated
them all behind `false`.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

src/client/Store.ts

@@ -14,7 +14,6 @@ import {
   groupCosmeticVariants,
   purchaseCosmetic,
   resolveCosmetics,
-  SUBSCRIPTIONS_ENABLED,
 } from "./Cosmetics";
 import { translateText } from "./Utils";
 
@@ -35,14 +34,7 @@ export class StoreModal extends BaseModal {
     return {
       tabs: [
         { key: "packs", label: translateText("store.packs") },
-        ...(SUBSCRIPTIONS_ENABLED
-          ? [
-              {
-                key: "subscriptions",
-                label: translateText("store.subscriptions"),
-              },
-            ]
-          : []),
+        { key: "subscriptions", label: translateText("store.subscriptions") },
         { key: "patterns", label: translateText("store.patterns") },
         { key: "flags", label: translateText("store.flags") },
         { key: "effects", label: translateText("store.effects") },