refactor: consolidate CLI entry points into dedicated cli/ directory

Move `database` and `setup` CLI scripts from their respective feature
directories into a unified `src/cli/` directory. Update `tsup.config.js`
build entries and `package.json` bin paths to reflect the new locations.

package.json

@@ -23,8 +23,8 @@
     "prepublishOnly": "npm run build"
   },
   "bin": {
-    "zen-db": "./dist/core/database/cli.js",
-    "zen-setup": "./dist/features/setup/cli.js"
+    "zen-db": "./dist/cli/database.js",
+    "zen-setup": "./dist/cli/setup.js"
   },
   "dependencies": {
     "@headlessui/react": "^2.0.0",