[V5] openbb-cli: Modular OpenAPI Refs (#7589)

* follow up to #7585

* add another codegen test

cli/openbb_cli/cli.py

@@ -455,6 +455,14 @@ def _generate_spec(
     else:
         source_url = server_url.rstrip("/") + "/openapi.json"
     spec_doc = build_spec_document(openapi, base_url=server_url, source_url=source_url)
+    if not spec_doc["commands"]:
+        sys.stderr.write(
+            f"generated 0 commands from {source_url} — the document exposes no "
+            "GET/POST operations OpenBB can map. Multi-file specs that split "
+            "paths across documents with external $refs must be bundled into "
+            "a single file first.\n"
+        )
+        return 2
     write_spec(output_path, spec_doc)
     sys.stdout.write(f"wrote {len(spec_doc['commands'])} commands to {output_path}\n")
     return 0
@@ -539,6 +547,13 @@ def _generate_extension(
 
     spec_doc = load_spec(spec_path)
     original_count = len(spec_doc.get("commands") or {})
+    if original_count == 0:
+        sys.stderr.write(
+            f"--generate-extension: spec at {spec_path} contains 0 commands — "
+            "nothing to generate. Regenerate the spec against a source that "
+            "exposes GET/POST operations.\n"
+        )
+        return 2
     spec_doc = _filter_spec_commands(spec_doc, include=include, exclude=exclude)
     filtered_count = len(spec_doc.get("commands") or {})
     if (include or exclude) and filtered_count == 0: