Add initial Nebula Browser project skeleton: CMakeLists to configure and link CEF (including post-build steps to copy runtime and UI files), a Windows CEF-based entry (app/main.cpp) that initializes CEF and loads the bundled UI, and a full ui/ and assets/ tree (HTML, CSS, JS, fonts, icons, and branding images). Update .gitignore to ignore build/out, thirdparty/cef, IDE and common OS artifacts.
Introduced a search engine selector dropdown in the search bar, allowing users to choose between Google, Bing, and DuckDuckGo. Updated the search logic to use the selected engine and added corresponding SVG icons. Adjusted CSS and HTML structure to accommodate the new selector.