Remove the Logcat viewer

[rz-openai]

Summary

Removes the unused Logcat viewer and its isolated implementation from the macOS app.

• Delete the 21 Logcat-specific Swift source files, including the streaming, filtering, crash-viewer, and persistence code.
• Remove the Logcat window scene, external-event registration, Tools-menu item, and keyboard shortcut.
• Remove the now-unused Logcat logger category.

This reduces the app's maintenance and input-parsing surface without affecting capture or Network Inspector functionality.

Validation

• xcodebuild -project Snap-O.xcodeproj -scheme Snap-O CODE_SIGNING_ALLOWED=NO CODE_SIGNING_REQUIRED=NO build
• Verified there are no remaining Logcat source, filename, or compiled-source-list references.