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/jose/dist/webapi/jwe/compact/encrypt.js

@@ -0,0 +1,27 @@
+import { FlattenedEncrypt } from '../flattened/encrypt.js';
+export class CompactEncrypt {
+    #flattened;
+    constructor(plaintext) {
+        this.#flattened = new FlattenedEncrypt(plaintext);
+    }
+    setContentEncryptionKey(cek) {
+        this.#flattened.setContentEncryptionKey(cek);
+        return this;
+    }
+    setInitializationVector(iv) {
+        this.#flattened.setInitializationVector(iv);
+        return this;
+    }
+    setProtectedHeader(protectedHeader) {
+        this.#flattened.setProtectedHeader(protectedHeader);
+        return this;
+    }
+    setKeyManagementParameters(parameters) {
+        this.#flattened.setKeyManagementParameters(parameters);
+        return this;
+    }
+    async encrypt(key, options) {
+        const jwe = await this.#flattened.encrypt(key, options);
+        return [jwe.protected, jwe.encrypted_key, jwe.iv, jwe.ciphertext, jwe.tag].join('.');
+    }
+}