fix: fall back to default certs when CA bundle path doesn't exist (#7352)

_resolve_verify() returned stale CA bundle paths from auth.json without
checking if the file exists. When a user logs into Nous Portal on their
host (where SSL_CERT_FILE points to a valid cert), that path gets
persisted in auth.json. Running hermes model later in Docker where the
host path doesn't exist caused FileNotFoundError bubbling up as
'Could not verify credentials: [Errno 2] No such file or directory'.

Now _resolve_verify validates the path exists before returning it. If
missing, logs a warning and falls back to True (default certifi-based
TLS verification).

hermes_cli/auth.py

@@ -1513,7 +1513,15 @@ def _resolve_verify(
     if effective_insecure:
         return False
     if effective_ca:
-        return str(effective_ca)
+        ca_path = str(effective_ca)
+        if not os.path.isfile(ca_path):
+            import logging
+            logging.getLogger("hermes.auth").warning(
+                "CA bundle path does not exist: %s — falling back to default certificates",
+                ca_path,
+            )
+            return True
+        return ca_path
     return True