fix(ui): remove duplicate Let-Claude entry point and icon collision

Context-menu "Let Claude handle it" on list rows duplicated the header
button; both routed to the same ListsIslandViewModel command via the
shell, so only the context menu entry (and its now-unused locale key)
is removed. The header button also shared Icon.Broom with Clear Day —
gave it Icon.AgentSuggested instead.

src/ClaudeDo.Ui/Views/Islands/TasksIslandView.axaml

@@ -35,7 +35,7 @@
           </Button>
           <Button Classes="icon-btn" IsVisible="{Binding IsLetClaudeVisible}"
                   Command="{Binding LetClaudeHandleCommand}" ToolTip.Tip="{loc:Tr tasks.letClaudeTip}">
-            <PathIcon Width="15" Height="15" Data="{StaticResource Icon.Broom}"/>
+            <PathIcon Width="15" Height="15" Data="{StaticResource Icon.AgentSuggested}"/>
           </Button>
           <Button Classes="icon-btn" IsVisible="{Binding IsMyDayList}"
                   Command="{Binding ClearDayCommand}" ToolTip.Tip="{loc:Tr tasks.clearDayTip}">