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/node-server/dist/globals.mjs

@@ -0,0 +1,5 @@
+// src/globals.ts
+import crypto from "crypto";
+if (typeof global.crypto === "undefined") {
+  global.crypto = crypto;
+}