refactor: clean up code formatting and update package dependencies

- Removed unnecessary blank lines and improved formatting for better readability in index.ts and converters.ts.
- Updated package-lock.json to downgrade several dependencies for compatibility, including @protobufjs/eventemitter, @protobufjs/fetch, and others.
- Enhanced error message in core.ts to clarify configuration options for the Command Code API key.
- Added a test to ensure the correct handling of environment variable values in test-stream.ts.

index.ts

@@ -33,7 +33,6 @@ const streamCommandCode = createStreamCommandCode({
 // ---------------------------------------------------------------------------
 
 export default async function (pi: ExtensionAPI) {
-
   const models = await fetchCommandCodeModels({ url: MODELS_URL })
 
   pi.registerProvider("commandcode", {