feat: added --disable-size flag and related handling

[yetanotheraryan]

For #240

Changes

• Added disableSize to the CLI config interface and default config.
• Registered the --disable-size option in CLI help/options.
• Passed CLI config into ResultsUi so result rendering can react to disableSize.
• Updated result display to show placeholder size text when size calculation is disabled.
• Updated UI scan flow to skip calculateFolderStats() when disableSize is enabled.
• Updated --delete-all handling so folders can be deleted as soon as they are found when size calculation is disabled.
• Updated test config fixture to include the new disableSize field.

Validation

• npm run build passes.
• npm test passes.
• Verified node lib/index.js --help shows --disable-size.

Note

--disable-size currently affects interactive UI mode.