Initial project scaffold: Rust egui ePub reader

- Cargo.toml with eframe, egui, epub, rfd, serde dependencies
- Source modules: app, book, font, persistence, reader, theme
- MinGW static linking config
- .gitignore for build artifacts

src/app.rs

@@ -0,0 +1,11 @@
+pub struct App;
+
+impl App {
+    pub fn new(_cc: &eframe::CreationContext) -> Self {
+        Self
+    }
+}
+
+impl eframe::App for App {
+    fn update(&mut self, _ctx: &egui::Context, _frame: &mut eframe::Frame) {}
+}