feat: initial impl of file proxy

apps/file-proxy/auth.ts

@@ -0,0 +1,14 @@
+import { createMiddleware } from "hono/factory"
+
+export type ApiKeyContextVariable = {
+	apiKey: string
+}
+
+const apiKeyMiddleware = createMiddleware<{ Variables: ApiKeyContextVariable }>(
+	async (c, next) => {
+		c.set("apiKey", process.env.API_KEY)
+		await next()
+	},
+)
+
+export { apiKeyMiddleware }