refactor: Update GUI components and integrate new palette widget

- Removed references to the old `EnhancedPaletteEditor` and replaced it with the new `PaletteWidget` across various files, including canvas and context menu implementations.
- Updated CMake configurations to include the new `palette_widget` source files, ensuring proper integration into the build system.
- Refactored GUI code to enhance modularity and maintainability, improving the overall user experience in palette management and editing functionalities.
- Introduced new UI components for background rendering and editor selection dialogs, enhancing the application's graphical interface.

src/app/gui/background_renderer.h

@@ -1,96 +0,0 @@
-#ifndef YAZE_APP_GUI_BACKGROUND_RENDERER_H
-#define YAZE_APP_GUI_BACKGROUND_RENDERER_H
-
-#include "imgui/imgui.h"
-#include "app/gui/color.h"
-
-namespace yaze {
-namespace gui {
-
-/**
- * @class BackgroundRenderer
- * @brief Renders themed background effects for docking windows
- */
-class BackgroundRenderer {
-public:
-  struct GridSettings {
-    float grid_size = 32.0f;           // Size of grid cells
-    float line_thickness = 1.0f;      // Thickness of grid lines
-    float opacity = 0.12f;            // Subtle but visible opacity
-    float fade_distance = 400.0f;     // Distance over which grid fades
-    bool enable_animation = false;    // Animation toggle (default off)
-    bool enable_breathing = false;    // Color breathing effect toggle (default off)
-    bool radial_fade = true;          // Re-enable subtle radial fade
-    bool enable_dots = false;         // Use dots instead of lines
-    float dot_size = 2.0f;            // Size of grid dots
-    float animation_speed = 1.0f;     // Animation speed multiplier
-    float breathing_speed = 1.5f;     // Breathing effect speed
-    float breathing_intensity = 0.3f; // How much color changes during breathing
-  };
-  
-  static BackgroundRenderer& Get();
-  
-  // Main rendering functions
-  void RenderDockingBackground(ImDrawList* draw_list, const ImVec2& window_pos, 
-                              const ImVec2& window_size, const Color& theme_color);
-  void RenderGridBackground(ImDrawList* draw_list, const ImVec2& window_pos, 
-                           const ImVec2& window_size, const Color& grid_color);
-  void RenderRadialGradient(ImDrawList* draw_list, const ImVec2& center, 
-                           float radius, const Color& inner_color, const Color& outer_color);
-  
-  // Configuration
-  void SetGridSettings(const GridSettings& settings) { grid_settings_ = settings; }
-  const GridSettings& GetGridSettings() const { return grid_settings_; }
-  
-  // Animation
-  void UpdateAnimation(float delta_time);
-  void SetAnimationEnabled(bool enabled) { grid_settings_.enable_animation = enabled; }
-  
-  // Theme integration
-  void UpdateForTheme(const Color& primary_color, const Color& background_color);
-  
-  // UI for settings
-  void DrawSettingsUI();
-  
-private:
-  BackgroundRenderer() = default;
-  
-  GridSettings grid_settings_;
-  float animation_time_ = 0.0f;
-  Color cached_grid_color_{0.5f, 0.5f, 0.5f, 0.1f};
-  
-  // Helper functions
-  float CalculateRadialFade(const ImVec2& pos, const ImVec2& center, float max_distance) const;
-  ImU32 BlendColorWithFade(const Color& base_color, float fade_factor) const;
-  void DrawGridLine(ImDrawList* draw_list, const ImVec2& start, const ImVec2& end, 
-                   ImU32 color, float thickness) const;
-  void DrawGridDot(ImDrawList* draw_list, const ImVec2& pos, ImU32 color, float size) const;
-};
-
-/**
- * @class DockSpaceRenderer
- * @brief Enhanced docking space with themed background effects
- */
-class DockSpaceRenderer {
-public:
-  static void BeginEnhancedDockSpace(ImGuiID dockspace_id, const ImVec2& size = ImVec2(0, 0), 
-                                    ImGuiDockNodeFlags flags = 0);
-  static void EndEnhancedDockSpace();
-  
-  // Configuration
-  static void SetBackgroundEnabled(bool enabled) { background_enabled_ = enabled; }
-  static void SetGridEnabled(bool enabled) { grid_enabled_ = enabled; }
-  static void SetEffectsEnabled(bool enabled) { effects_enabled_ = enabled; }
-  
-private:
-  static bool background_enabled_;
-  static bool grid_enabled_;
-  static bool effects_enabled_;
-  static ImVec2 last_dockspace_pos_;
-  static ImVec2 last_dockspace_size_;
-};
-
-} // namespace gui
-} // namespace yaze
-
-#endif // YAZE_APP_GUI_BACKGROUND_RENDERER_H