Sign panel sessions and isolate test runs

- Replace in-memory auth sessions with signed cookies and signed OAuth state
- Add auth route coverage and update panel/web server wiring
- Switch test script to per-file Bun processes and clean up type checks

bot/modules/economy/shop.view.ts

@@ -163,8 +163,9 @@ export function getShopListingMessage(
 
             if (line) {
                 if (!tiers[rarity]) tiers[rarity] = { items: [], totalChance: 0 };
-                tiers[rarity].items.push(line);
-                tiers[rarity].totalChance += chance;
+                const tier = tiers[rarity]!;
+                tier.items.push(line);
+                tier.totalChance += chance;
             }
         }