[1.2.1] CLI: Concise version output

Patch release of @simple-post/cli with concise, consistent version output.

npm install -g @simple-post/cli@1.2.1
simplepost -v
# 1.2.1

Fixed

• Added simplepost -v as a version shortcut
• Changed simplepost --version to print only the package version instead of the oclif user-agent string
• Added command-level tests covering both version flags

See the changelog and CLI guide.