feat(API-11): Route API calls through AgilitonAPI gateway

Add gateway-first pattern: when AGILITON_API_KEY is set, route all
external API calls through the gateway with X-API-Key auth. Falls back
to direct API access when gateway is unavailable.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

node_modules/hono/dist/utils/handler.js

@@ -0,0 +1,13 @@
+// src/utils/handler.ts
+import { COMPOSED_HANDLER } from "./constants.js";
+var isMiddleware = (handler) => handler.length > 1;
+var findTargetHandler = (handler) => {
+  return handler[COMPOSED_HANDLER] ? (
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    findTargetHandler(handler[COMPOSED_HANDLER])
+  ) : handler;
+};
+export {
+  findTargetHandler,
+  isMiddleware
+};