Refactoring and introducing tool manager for linux

[Eashan-H]

Summary

This PR refactors the Tool Manager to use a platform-specific backend architecture and introduces a dedicated Linux backend for native tool management. Platform-dependent logic has been separated into backend modules, making the codebase cleaner, easier to maintain, and easier to extend to additional operating systems.

The Linux backend supports native tool check, install, update, and uninstall operations on Debian/Ubuntu (APT), Fedora/RHEL (DNF), openSUSE (Zypper), and Arch Linux (Pacman). The Tool Manager now delegates platform-specific operations to the appropriate backend while preserving the existing GUI workflow.

Changes

Refactoring

Platform-specific Tool Manager logic has been moved into dedicated backend modules.

A common abstraction layer now allows the GUI to interact with the appropriate backend regardless of the host operating system.

main.py has been simplified by delegating platform-specific operations to backend implementations, providing a scalable foundation for future Windows and macOS support.

New File: src/toolManager/tool_manager_linux.py

A self-contained CLI backend responsible for Linux package management.

Supports automatic detection of APT, DNF, Zypper, and Pacman.

Uses a PACKAGE_MAP dictionary to translate logical tool names such as ngspice, kicad, and verilator into the correct distribution-specific package names.

Detects WSL environments and adapts privilege escalation accordingly.

Uses pkexec when available in graphical environments and falls back to sudo -S for WSL and headless systems.

Avoids using pkexec when no D-Bus or PolicyKit agent is available.

Resolves binaries safely under WSL by ignoring Windows executables mounted under /mnt.

Serializes APT operations using fcntl.flock to prevent concurrent package manager conflicts.

Streams package manager output in real time so installation progress is visible in the GUI.

Implements check, install, update, and uninstall operations.