feat(cli): add script eval command for evaluating Script API expressions

[clavery]

Summary

• Adds b2c script eval command to evaluate arbitrary Script API expressions on B2C Commerce instances
• Implements SDAPI (Script Debugger API) client for remote script debugging operations
• Uses a hybrid approach: injects a controller to provide a breakpoint target, then uses SDAPI debugger eval

New Features

CLI Command

# Inline expression
b2c script eval "dw.system.Site.getCurrent().getName()"

# From file
b2c script eval --file script.js

# From stdin
echo 'dw.system.Site.current.getID()' | b2c script eval

# With options
b2c script eval --site RefArch --timeout 60 "1+1"

SDK Modules

• @salesforce/b2c-tooling-sdk/clients - SDAPI client for debugger operations
• @salesforce/b2c-tooling-sdk/operations/script - Eval and controller injection operations
• @salesforce/b2c-tooling-sdk/operations/sites - Site cartridge path operations

Implementation Details

• Fallback chain for controller injection: Modifies existing Default.js → Adds to existing cartridge → Creates new cartridge
• Proper cleanup: Uses DELETE /client to remove breakpoints, resume threads, and disable debugger
• Error detection: Detects runtime script errors (ReferenceError, TypeError, etc.) in eval results
• Multi-statement support: Wraps multi-statement code in Function constructor with auto-return