feat(ui): open Weekly Report modal from the menu

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

src/ClaudeDo.Ui/Views/MainWindow.axaml

@@ -65,6 +65,7 @@
                         Command="{Binding RestartWorkerCommand}"/>
               <MenuItem Header="Worktrees…"
                         Command="{Binding OpenWorktreesOverviewGlobalCommand}"/>
+              <MenuItem Header="Wochenbericht…" Command="{Binding OpenWeeklyReportCommand}"/>
               <MenuItem Header="About…" Command="{Binding OpenAboutCommand}"/>
               <MenuItem Header="Add repos as lists…" Command="{Binding OpenRepoImportCommand}"/>
             </MenuItem>