Implement macOS-specific support for the ProcessMemory plugin and update plugin discovery/build.
- Add macOS build/install support: include plugins/ProcessMemory in top-level CMake and copy the built plugin into Reclass.app/Contents/PlugIns on macOS.
- Implement Apple-specific ProcessMemoryProvider: task_for_pid usage, mach_vm_read_overwrite/mach_vm_write, proc_pidpath/proc_regionfilename based module caching, region enumeration, symbol formatting, module enumeration, and proper cleanup (mach_port_deallocate).
- Extend plugin header to track m_task and adjust readability checks for macOS.
- Add macOS handling in getInitialBaseAddress and process enumeration to find base addresses and processes using proc APIs.
- Improve PluginManager to probe multiple plugin locations (including Contents/PlugIns inside macOS bundles), aggregate/log candidate counts, and continue scanning multiple dirs.
- Add macOS screenshot to README (docs/README_PIC6.png) and reference it in README.
These changes enable the ProcessMemory plugin to operate on macOS and make plugin discovery more robust on macOS app bundles.
