chore(release): move the v2 line from alpha.0 to beta.0

The skeleton story's scope is complete, so the prerelease line matches the
plan of shipping 2.0.0-beta.N until GA. Both spellings already route to the
beta dist-tag, so this changes the label rather than the destination.

#claude_code#
🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: naeem-shakh-cs

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "@contentstack/cli-launch",
-  "version": "2.0.0-alpha.0",
+  "version": "2.0.0-beta.0",
   "description": "Launch related operations",
   "author": "Contentstack CLI",
   "bin": {