chore: bump version to 0.5.0

[vigneshrajsb]

Summary

• Bumps to 0.5.0 for the newly merged Sites private-access-control feature (Add Sites visibility commands #10): sites visibility command, sites create --visibility support, and the create-time confirmation fix for accounts that default to public.
• Minor bump: new feature (Sites visibility command), no breaking changes to the CLI's own interface.

Test plan

• pnpm typecheck / pnpm test (97/97) / pnpm build all pass