chore: overhaul infrastructure and integrate @mintel packages

- Restructure to pnpm monorepo (site moved to apps/web)
- Integrate @mintel/tsconfig, @mintel/eslint-config, @mintel/husky-config
- Implement Docker service architecture (Varnish, Directus, Gatekeeper)
- Setup environment-aware Gitea Actions deployment

apps/web/src/utils/cache/memory-adapter.ts

@@ -0,0 +1,43 @@
+/**
+ * Memory Cache Adapter
+ * Simple in-memory implementation
+ */
+
+import type { CacheAdapter, CacheConfig } from './interfaces';
+
+export class MemoryCacheAdapter implements CacheAdapter {
+  private cache = new Map<string, { value: any; expiry: number }>();
+  private defaultTTL: number;
+
+  constructor(config: CacheConfig = {}) {
+    this.defaultTTL = config.defaultTTL || 3600;
+  }
+
+  async get<T>(key: string): Promise<T | null> {
+    const item = this.cache.get(key);
+    if (!item) return null;
+
+    if (Date.now() > item.expiry) {
+      this.cache.delete(key);
+      return null;
+    }
+
+    return item.value as T;
+  }
+
+  async set<T>(key: string, value: T, ttl?: number): Promise<void> {
+    const finalTTL = ttl || this.defaultTTL;
+    this.cache.set(key, {
+      value,
+      expiry: Date.now() + (finalTTL * 1000)
+    });
+  }
+
+  async del(key: string): Promise<void> {
+    this.cache.delete(key);
+  }
+
+  async clear(): Promise<void> {
+    this.cache.clear();
+  }
+}