[studio] Add confirmation dialog for file deletion, move deletion to Project

src/olympic/studio/modlib/include/studio/project.hpp

@@ -45,7 +45,7 @@ constexpr ox::StringView parentDir(ox::StringView path) noexcept {
 	return substr(path, 0, extStart);
 }
 
-class Project {
+class Project: public ox::SignalHandler {
 	private:
 		ox::SmallMap<ox::String, ox::Optional<ox::ClawFormat>> m_typeFmt;
 		keel::Context &m_ctx;
@@ -91,6 +91,8 @@ class Project {
 
 		ox::Result<ox::FileStat> stat(ox::StringViewCR path) const noexcept;
 
+		ox::Error deleteItem(ox::StringViewCR path) noexcept;
+
 		[[nodiscard]]
 		bool exists(ox::StringViewCR path) const noexcept;