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/package.json

@@ -0,0 +1,23 @@
+{
+  "name": "lexai-cli",
+  "version": "1.0.0",
+  "description": "LexAI Prompt Builder CLI — improve a rough idea into a paste-ready prompt before you fire it",
+  "private": true,
+  "type": "module",
+  "bin": {
+    "lexai": "./out/cli.js"
+  },
+  "engines": {
+    "node": ">=22"
+  },
+  "scripts": {
+    "compile": "node esbuild.mjs",
+    "build": "node esbuild.mjs",
+    "typecheck": "tsc --noEmit"
+  },
+  "devDependencies": {
+    "@types/node": "^22.13.4",
+    "esbuild": "^0.25.0",
+    "typescript": "^5.7.3"
+  }
+}