Add debug/testing utilities for network packet inspection and first-ever
test coverage for the network monitoring area, as discussed in #2592.
- SafePacket: managed wrapper with bounds checking and lifetime safety
- NetworkPointerValidator: debug utility for pointer address validation
- Make NetworkMonitorWidget.IsFiltered internal static for testability
- Add 49 unit tests covering SafePacket, pointer validation, and opcode
filter parsing (ranges, exclusions, complex filters)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
