feat: add Report/About/Changelog buttons to Support ribbon group

- REPORT opens GitHub new-issue page
- ABOUT opens a dialog window with version, OS and arch info + Copy Info button
- CHANGELOG opens GitHub releases page
- Fix Windows build: add windows-sys as target-specific dependency for PRINT command

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

src/ui/about.rs

@@ -0,0 +1,96 @@
+use crate::app::Message;
+use iced::widget::{button, column, container, row, text, Space};
+use iced::{Background, Border, Color, Element, Fill, Theme};
+
+const BG:     Color = Color { r: 0.15, g: 0.15, b: 0.15, a: 1.0 };
+const PANEL:  Color = Color { r: 0.12, g: 0.12, b: 0.12, a: 1.0 };
+const BORDER: Color = Color { r: 0.30, g: 0.30, b: 0.30, a: 1.0 };
+const DIM:    Color = Color { r: 0.55, g: 0.55, b: 0.55, a: 1.0 };
+const ACCENT: Color = Color { r: 0.25, g: 0.50, b: 0.85, a: 1.0 };
+const WHITE:  Color = Color { r: 0.92, g: 0.92, b: 0.92, a: 1.0 };
+
+fn info_row<'a>(label: &'static str, value: String) -> Element<'a, Message> {
+    row![
+        text(label).size(11).color(DIM).width(100),
+        text(value).size(11).color(WHITE),
+    ]
+    .spacing(8)
+    .align_y(iced::Center)
+    .padding([3, 0])
+    .into()
+}
+
+pub fn view_window<'a>() -> Element<'a, Message> {
+    let version   = env!("CARGO_PKG_VERSION");
+    let os        = std::env::consts::OS;
+    let arch      = std::env::consts::ARCH;
+
+    let logo = container(
+        column![
+            text("H7CAD").size(32).color(ACCENT),
+            text("CAD application for Architecture & Engineering")
+                .size(11).color(DIM),
+        ]
+        .spacing(4)
+        .align_x(iced::Center),
+    )
+    .width(Fill)
+    .padding(iced::Padding { top: 20.0, right: 0.0, bottom: 16.0, left: 0.0 })
+    .align_x(iced::Center);
+
+    let info_block = container(
+        column![
+            info_row("Version",   format!("v{}", version)),
+            info_row("Platform",  os.to_string()),
+            info_row("Arch",      arch.to_string()),
+        ]
+        .spacing(2)
+        .padding([12, 16]),
+    )
+    .width(Fill)
+    .style(|_: &Theme| container::Style {
+        background: Some(Background::Color(PANEL)),
+        border: Border {
+            color: BORDER,
+            width: 1.0,
+            radius: 4.0.into(),
+        },
+        ..Default::default()
+    });
+
+    let copy_btn = button(
+        text("Copy Info").size(11),
+    )
+    .on_press(Message::AboutCopyInfo)
+    .style(|_: &Theme, st| button::Style {
+        background: Some(Background::Color(match st {
+            button::Status::Hovered | button::Status::Pressed =>
+                Color { r: 0.20, g: 0.42, b: 0.72, a: 1.0 },
+            _ => ACCENT,
+        })),
+        text_color: WHITE,
+        border: Border { radius: 4.0.into(), ..Default::default() },
+        ..Default::default()
+    })
+    .padding([6, 16]);
+
+    let footer = row![
+        Space::new().width(Fill),
+        copy_btn,
+    ]
+    .align_y(iced::Center)
+    .padding(iced::Padding { top: 12.0, right: 0.0, bottom: 0.0, left: 0.0 });
+
+    container(
+        column![logo, info_block, footer]
+            .spacing(0)
+            .padding(iced::Padding { top: 0.0, right: 20.0, bottom: 20.0, left: 20.0 }),
+    )
+    .style(|_: &Theme| container::Style {
+        background: Some(Background::Color(BG)),
+        ..Default::default()
+    })
+    .width(Fill)
+    .height(Fill)
+    .into()
+}

src/ui/mod.rs

@@ -2,6 +2,7 @@
 /// Change this to scale the ribbon, layer manager rows, and property panel rows uniformly.
 pub const ROW_H: f32 = 26.0;
 
+pub mod about;
 pub mod app_menu;
 pub mod command_line;
 pub mod dimstyle;