feat: Add Hyprland support and improve Wayland compatibility

[JaINTP]

Description

This PR introduces native support for the Hyprland compositor and addresses several issues related to running floww in pure Wayland environments.

Key Changes:

• Hyprland Backend: Added a new workspace management backend that uses hyprctl. It is automatically prioritized when a Hyprland session is detected (via the HYPRLAND_INSTANCE_SIGNATURE environment variable).
• Robust Environment Detection: Modified the ewmhlib import logic to catch all exceptions. Previously, the application could crash on startup in Wayland environments if ewmhlib (via python-xlib) attempted to connect to a non-existent X11 display.
• Config Isolation Fix: Fixed a bug in ConfigManager where DEFAULT_CONFIG was being mutated globally during merging. This was causing state leakage between unit tests and intermittent failures.
• Improved Workspace Querying: Implemented _get_total_workspaces_with_hyprctl using hyprctl workspaces -j to accurately determine the workspace count for numeric switching.

Motivation

floww relied primarily on X11-specific tools (ewmhlib/wmctrl). This update makes the tool viable for Hyprland users while making the core logic more resilient to Wayland-only setups.

Testing

• Added tests/test_workspace_manager.py with 6 new unit tests covering:
  • Initialization under different WM environments.
  • Successful and failed workspace switching via hyprctl.
  • Correct parsing of workspace counts from Hyprland JSON output.
• Verified that all 55 project tests pass using make test.
• Verified code style consistency using make lint (ruff).

Checklist

• Code follows the existing style of the project.
• Tests have been added to cover changes.
• All tests pass locally.
• Linting passes locally.