fix(setup): add Close and Launch Now buttons after install completes

The wizard previously reached Stage::Finished and showed a status
message with no way to proceed — the user was stuck. Now:

- A Close button exits the setup window
- A Launch Now button (enabled only when the exe exists) launches
  the newly installed launcher and closes the wizard

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/setup.rs

@@ -27,6 +27,9 @@ pub enum Message {
     InstallPressed,
     InstallDone(Result<i32, String>),
     Tick,
+    // Finished stage
+    LaunchNow,
+    Close,
 }
 
 #[derive(Debug, Clone)]
@@ -282,7 +285,6 @@ fn update(state: &mut State, message: Message) -> Task<Message> {
             )
         }
         Message::InstallDone(res) => {
-            state.stage = Stage::Finished;
             let launcher = state
                 .launcher
                 .as_ref()
@@ -294,6 +296,9 @@ fn update(state: &mut State, message: Message) -> Task<Message> {
                     state.config.launchers.push(launcher.clone());
                     let _ = state.config.save();
                 }
+                state.stage = Stage::Finished;
+            } else {
+                state.stage = Stage::Finished;
             }
             // Always clean up downloaded temp file
             if let Some(tmp) = state.downloaded_temp.take() {
@@ -301,10 +306,8 @@ fn update(state: &mut State, message: Message) -> Task<Message> {
             }
             state.status = match res {
                 Ok(code) if exe.exists() => format!(
-                    "✓ Installer finished (umu exit {code}); {} is present.\n\
-                     You can now run: umutray launch {}",
-                    exe.display(),
-                    launcher.name,
+                    "✓ Installer finished (exit {code}). {} is ready.",
+                    launcher.display,
                 ),
                 Ok(code) => format!(
                     "umu-run exited {code} but the expected exe is not at {}.\n\
@@ -315,6 +318,17 @@ fn update(state: &mut State, message: Message) -> Task<Message> {
             };
             Task::none()
         }
+        Message::LaunchNow => {
+            if let Some(launcher) = &state.launcher {
+                let config = state.config.clone();
+                let launcher = launcher.clone();
+                std::thread::spawn(move || {
+                    let _ = crate::launcher::launch(&config, &launcher);
+                });
+            }
+            iced::exit()
+        }
+        Message::Close => iced::exit(),
     }
 }
 
@@ -427,6 +441,11 @@ fn view_install(state: &State) -> Element<'_, Message> {
 
     let prepare_enabled = matches!(state.stage, Stage::Idle | Stage::Ready | Stage::Finished);
     let install_enabled = matches!(state.stage, Stage::Ready);
+    let finished = matches!(state.stage, Stage::Finished);
+    let install_success = finished
+        && launcher
+            .full_exe_path()
+            .exists();
 
     let prepare_btn = button(text("Download / Prepare"))
         .on_press_maybe(prepare_enabled.then_some(Message::PreparePressed));
@@ -473,6 +492,18 @@ fn view_install(state: &State) -> Element<'_, Message> {
         text("").into()
     };
 
+    let finished_row: Element<Message> = if finished {
+        let close_btn = button(text("Close").size(13))
+            .on_press(Message::Close)
+            .style(button::secondary);
+        let launch_btn = button(text("Launch now").size(13))
+            .on_press_maybe(install_success.then_some(Message::LaunchNow))
+            .style(button::primary);
+        row![close_btn, launch_btn].spacing(10).into()
+    } else {
+        text("").into()
+    };
+
     let body = column![
         header,
         prefix,
@@ -482,6 +513,7 @@ fn view_install(state: &State) -> Element<'_, Message> {
         row![prepare_btn, install_btn].spacing(12),
         progress_row,
         status,
+        finished_row,
         log_pane,
     ]
     .spacing(12)