细化书签功能：正文指示器、侧边栏书签列表、跳转功能

src/app.rs

@@ -275,9 +275,12 @@ BgType::Custom(ref path) if !path.is_empty() => {
          let theme_copy = self.settings.theme;
          let profile_names: Vec<String> = self.settings.profiles.iter().map(|p| p.name.clone()).collect();
 
+         let bookmarks = self.settings.bookmarks.get(&file_path).cloned().unwrap_or_default();
+         let mut jump_to_bookmark: Option<usize> = None;
+
          egui::CentralPanel::default().show(ctx, |ui| {
              let book = self.state.book.as_mut().unwrap();
-             let action = crate::reader::reading_view(
+             let (action, jump) = crate::reader::reading_view(
                  ui,
                  book,
                  &mut self.state.current_section,
@@ -288,7 +291,9 @@ BgType::Custom(ref path) if !path.is_empty() => {
                  bg_type.clone(),
                  &file_path,
                  &profile_names,
+                 &bookmarks,
              );
+             jump_to_bookmark = jump;
 
              if action.go_back {
                  self.save_reading_position();
@@ -347,8 +352,49 @@ BgType::Custom(ref path) if !path.is_empty() => {
              if action.page_next {
                  self.state.next_page();
              }
+
+             if action.toggle_bookmark {
+                 let file_path = file_path.clone();
+                 let section = self.state.current_section;
+                 let page = self.state.current_page;
+                 let book = self.state.book.as_ref().unwrap();
+                 let section_title = book.sections.get(section)
+                     .map(|s| s.title.clone())
+                     .unwrap_or_else(|| format!("第{}章", section + 1));
+
+                 let bookmarks = self.settings.bookmarks.entry(file_path)
+                     .or_insert_with(Vec::new);
+
+                 let existing_idx = bookmarks.iter()
+                     .position(|b: &theme::Bookmark| b.section == section && b.page == page);
+
+                 if let Some(idx) = existing_idx {
+                     bookmarks.remove(idx);
+                 } else {
+                     use std::time::{SystemTime, UNIX_EPOCH};
+                     let timestamp = SystemTime::now()
+                         .duration_since(UNIX_EPOCH)
+                         .map(|d| d.as_secs() as i64)
+                         .unwrap_or(0);
+                     bookmarks.push(theme::Bookmark {
+                         section,
+                         page,
+                         label: format!("{} - 第{}页", section_title, page + 1),
+                         timestamp,
+                     });
+                 }
+             }
          });
 
+         if let Some(idx) = jump_to_bookmark {
+             if let Some(bookmarks) = self.settings.bookmarks.get(&file_path) {
+                 if let Some(bm) = bookmarks.get(idx) {
+                     self.state.current_section = bm.section;
+                     self.state.current_page = bm.page;
+                 }
+             }
+         }
+
          // Sync style changes back to active profile (outside closure)
          if let Some(p) = self.settings.profiles.iter_mut()
              .find(|p| p.name == self.settings.active_profile)