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/has-symbols/test/shams/core-js.js

@@ -0,0 +1,29 @@
+'use strict';
+
+var test = require('tape');
+
+if (typeof Symbol === 'function' && typeof Symbol() === 'symbol') {
+	test('has native Symbol support', function (t) {
+		t.equal(typeof Symbol, 'function');
+		t.equal(typeof Symbol(), 'symbol');
+		t.end();
+	});
+	// @ts-expect-error TS is stupid and doesn't know about top level return
+	return;
+}
+
+var hasSymbols = require('../../shams');
+
+test('polyfilled Symbols', function (t) {
+	/* eslint-disable global-require */
+	t.equal(hasSymbols(), false, 'hasSymbols is false before polyfilling');
+	require('core-js/fn/symbol');
+	require('core-js/fn/symbol/to-string-tag');
+
+	require('../tests')(t);
+
+	var hasSymbolsAfter = hasSymbols();
+	t.equal(hasSymbolsAfter, true, 'hasSymbols is true after polyfilling');
+	/* eslint-enable global-require */
+	t.end();
+});