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/object-inspect/example/inspect.js

@@ -0,0 +1,10 @@
+'use strict';
+
+/* eslint-env browser */
+var inspect = require('../');
+
+var d = document.createElement('div');
+d.setAttribute('id', 'beep');
+d.innerHTML = '<b>wooo</b><i>iiiii</i>';
+
+console.log(inspect([d, { a: 3, b: 4, c: [5, 6, [7, [8, [9]]]] }]));