feat(cli): add initial CLI implementation with argument parsing and prompt handling

- Created package.json and package-lock.json for CLI package.
- Implemented argument parsing in args.ts to handle various flags and commands.
- Developed main CLI logic in cli.ts to execute commands and handle errors.
- Added configuration loading from a JSON file in config.ts, with environment variable support.
- Implemented prompt resolution and provider interaction in prompt.ts.
- Added usage documentation for the CLI.
- Configured TypeScript settings in tsconfig.json for the CLI package.
- Updated README in vscode package to reflect the new CLI functionality.
- Refactored root tsconfig.json to streamline project structure.

packages/cli/esbuild.mjs

@@ -0,0 +1,35 @@
+import * as esbuild from 'esbuild';
+import { resolve, dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const watch = process.argv.includes('--watch');
+const libRoot = resolve(__dirname, '../../src/lib');
+
+/** @type {import('esbuild').BuildOptions} */
+const options = {
+  entryPoints: [resolve(__dirname, 'src/cli.ts')],
+  bundle: true,
+  outfile: resolve(__dirname, 'out/cli.js'),
+  format: 'esm',
+  platform: 'node',
+  target: 'node22',
+  sourcemap: true,
+  sourcesContent: false,
+  logLevel: 'info',
+  banner: {
+    js: '#!/usr/bin/env node',
+  },
+  alias: {
+    '@lib': libRoot,
+  },
+};
+
+if (watch) {
+  const ctx = await esbuild.context(options);
+  await ctx.watch();
+  console.log('[lexai-cli] watching…');
+} else {
+  await esbuild.build(options);
+  console.log('[lexai-cli] compiled → out/cli.js');
+}