Add verify command

[hongsh87]

Summary

Adds a unity-cli verify command that orchestrates common Unity validation checks:

• optional script refresh/compile check
• optional Play Mode entry
• runtime console error inspection
• automatic Play Mode stop when verify started it

Why

This gives agents and CLI users a single command for the common post-change Unity verification loop instead of manually chaining status, compile, play, console, and stop commands.

Validation

• go test ./...
• go run . verify --help
• Verified against a local Unity project with verify --skip-compile --skip-play and verify --skip-compile