refactor: remove reasoning file persistence and consolidate cursor methods

Remove reasoning-delta/end file writing and merge moveCursor/clearScreenDown
into a single moveClearReset method. Add config save confirmation message.

index.ts

@@ -2,6 +2,7 @@ import os from "node:os";
 import { parseArgs } from "node:util";
 import { createOpenAICompatible } from "@ai-sdk/openai-compatible";
 import { type ModelMessage, streamText } from "ai";
+import chalk from "chalk";
 
 import Renderer from "./src/render";
 
@@ -49,6 +50,7 @@ async function main() {
 
   if (saveConfig) {
     await configFile.write(JSON.stringify(config, null, "  "));
+    console.log(chalk.green("Configuration saved!"));
     return;
   }