feat: Introduce UI Helper Functions and Refactor Color Management

- Added ui_helpers.cc and ui_helpers.h to centralize UI-related helper functions, improving code organization and reducing boilerplate in ImGui usage.
- Refactored color management in BppFormatUI to utilize new helper functions for success, warning, and error colors, enhancing theming consistency.
- Updated AgentChatWidget and CanvasContextMenu to streamline UI rendering and improve maintainability by removing redundant code and enhancing functionality.
- Removed canvas_utils_moved.cc and canvas_utils_moved.h to clean up the project structure, consolidating utility functions into more appropriate locations.

src/app/gui/ui_helpers.cc

@@ -0,0 +1,72 @@
+#include "app/gui/ui_helpers.h"
+#include "app/gui/theme_manager.h"
+#include "app/gui/icons.h"
+#include "imgui/imgui.h"
+#include "imgui/imgui_internal.h"
+
+namespace yaze {
+namespace gui {
+
+ImVec4 GetThemeColor(ImGuiCol idx) {
+    return ImGui::GetStyle().Colors[idx];
+}
+
+ImVec4 GetSuccessColor() {
+    const auto& theme = ThemeManager::Get().GetCurrentTheme();
+    return ConvertColorToImVec4(theme.success);
+}
+
+ImVec4 GetWarningColor() {
+    const auto& theme = ThemeManager::Get().GetCurrentTheme();
+    return ConvertColorToImVec4(theme.warning);
+}
+
+ImVec4 GetErrorColor() {
+    const auto& theme = ThemeManager::Get().GetCurrentTheme();
+    return ConvertColorToImVec4(theme.error);
+}
+
+ImVec4 GetInfoColor() {
+    const auto& theme = ThemeManager::Get().GetCurrentTheme();
+    return ConvertColorToImVec4(theme.info);
+}
+
+ImVec4 GetAccentColor() {
+    const auto& theme = ThemeManager::Get().GetCurrentTheme();
+    return ConvertColorToImVec4(theme.accent);
+}
+
+void BeginField(const char* label) {
+    ImGui::BeginGroup();
+    ImGui::TextUnformatted(label);
+    ImGui::SameLine();
+    ImGui::PushItemWidth(ImGui::GetContentRegionAvail().x * 0.6f);
+}
+
+void EndField() {
+    ImGui::PopItemWidth();
+    ImGui::EndGroup();
+}
+
+bool IconButton(const char* icon, const char* label, const ImVec2& size) {
+    std::string button_text = std::string(icon) + " " + std::string(label);
+    return ImGui::Button(button_text.c_str(), size);
+}
+
+void HelpMarker(const char* desc) {
+    ImGui::TextDisabled(ICON_MD_HELP_OUTLINE);
+    if (ImGui::IsItemHovered()) {
+        ImGui::BeginTooltip();
+        ImGui::PushTextWrapPos(ImGui::GetFontSize() * 35.0f);
+        ImGui::TextUnformatted(desc);
+        ImGui::PopTextWrapPos();
+        ImGui::EndTooltip();
+    }
+}
+
+void SeparatorText(const char* label) {
+    ImGui::SeparatorText(label);
+}
+
+} // namespace gui
+} // namespace yaze