Stage 03.3 - exchangeInfo and symbol validation

app/src/integrations/exchange/exceptions.py

@@ -0,0 +1,13 @@
+from __future__ import annotations
+
+
+class ExchangeError(Exception):
+    """Base exchange integration error."""
+
+
+class ExchangeConnectionError(ExchangeError):
+    """HTTP/network/timeout level exchange error."""
+
+
+class ExchangeResponseError(ExchangeError):
+    """Unexpected HTTP response or malformed JSON."""