added decoder

apps/stock/data-ingestion/src/handlers/te/shared/decode.ts

@@ -0,0 +1,17 @@
+import { inflate } from 'pako';
+
+/**
+ * Decodes TE obfuscated data: base64 decode -> XOR with key -> inflate -> JSON parse
+ */
+export function decodeTEData<T = unknown>(b64Data: string, key: string): T | null {
+  try {
+    const raw = Array.from(atob(b64Data), (c) => c.charCodeAt(0));
+    const keyBytes = Array.from(new TextEncoder().encode(key));
+    const keyLen = keyBytes.length;
+    const xored = new Uint8Array(raw.map((byte, i) => byte ^ (keyBytes[i % keyLen] ?? 0)));
+
+    return JSON.parse(inflate(xored, { to: 'string' }));
+  } catch {
+    return null;
+  }
+}

apps/stock/data-ingestion/src/handlers/te/shared/index.ts

@@ -1,2 +1,3 @@
 export * from './config';
+export * from './decode';
 export * from './types';