feat: use new db site, cache requests to avoid repeated unneeded fetch calls

lib/db.ts

@@ -0,0 +1,28 @@
+export const DB_BASE_URL = 'https://dbd-db.neru.rip';
+
+const _cache = new Map<string, Promise<any>>();
+
+export function fetchDB<T = any>(path: string): Promise<T> {
+  if (!_cache.has(path)) {
+    _cache.set(
+      path,
+      fetch(`${DB_BASE_URL}${path}`)
+        .then(r => {
+          if (!r.ok) throw new Error(`[db] ${r.status} ${path}`);
+          return r.json();
+        })
+        .catch(err => {
+          _cache.delete(path); 
+          console.error(err);
+          return [];
+        })
+    );
+  }
+  return _cache.get(path)!;
+}
+
+export const fetchCharacters     = () => fetchDB('/data/characters.json');
+export const fetchCustomizations = () => fetchDB('/data/customization_items.json');
+export const fetchItems          = () => fetchDB('/data/items.json');
+export const fetchOfferings      = () => fetchDB('/data/offerings.json');
+export const fetchDLCs           = () => fetchDB('/data/dlcs.json');