Add log view UI with transaction entry form

Expense/Income toggle, amount entry, currency dropdown, category
dropdown (filtered by transaction type), date picker with calendar
popover, optional note field, save button, and recent transactions
placeholder section.

outlay-gtk/src/window.rs

@@ -1,9 +1,12 @@
 use adw::prelude::*;
 
+use crate::log_view::LogView;
+
 pub struct MainWindow {
     pub window: adw::ApplicationWindow,
     pub split_view: adw::NavigationSplitView,
     pub content_stack: gtk::Stack,
+    pub log_view: LogView,
 }
 
 struct SidebarItem {
@@ -26,7 +29,16 @@ impl MainWindow {
         let content_stack = gtk::Stack::new();
         content_stack.set_transition_type(gtk::StackTransitionType::Crossfade);
 
-        for item in SIDEBAR_ITEMS {
+        // Log view - real widget
+        let log_view = LogView::new();
+        let log_scroll = gtk::ScrolledWindow::builder()
+            .hscrollbar_policy(gtk::PolicyType::Never)
+            .child(&log_view.container)
+            .build();
+        content_stack.add_named(&log_scroll, Some("log"));
+
+        // Remaining pages are placeholders for now
+        for item in &SIDEBAR_ITEMS[1..] {
             let page = adw::StatusPage::builder()
                 .title(item.label)
                 .icon_name(item.icon)
@@ -98,6 +110,7 @@ impl MainWindow {
             window,
             split_view,
             content_stack,
+            log_view,
         }
     }