Adds a new bit validate command that runs check-types, lint, and test in sequence.

• Created new validator aspect in scopes/defender/validator
• Command stops at first failure and returns non-zero exit code (use --continue-on-error to run all checks)
• Shows detailed error output for each validation step
• By default validates only new/modified components, use --all for all components

Usage

bit validate                     # Validate modified/new components
bit validate --all               # Validate all components
bit validate --continue-on-error # Run all checks even when errors are found
bit validate [pattern]           # Validate specific components