- Add HistoryEntry struct with path, scroll_offset, selected_link fields
- Add Phase 3 navigation fields to App: history, history_index, link_records, selected_link, current_path
- Update App::new() to accept link_records and current_path parameters
- Implement navigate_to() with browser-style forward history truncation
- Implement navigate_back() and navigate_forward() with state restoration
- Implement follow_selected_link() for wiki-link and standard link resolution
- Implement select_next_link() and select_prev_link() with wrap-around
- Implement scroll_to_selected_link() for auto-scroll centering
- Add Tab, Shift-Tab, Enter, Backspace, Alt+Left, Alt+Right key bindings
- Update handle_resize() to capture and validate link_records after re-render
- Update main.rs to destructure link_records and pass to App::new()
- Remove #[allow(dead_code)] on config field (now actively used)
ruohki
