style(sw): drop the 취소 / 적용 footer from the viewer options popup

Options already apply on every toggle, input and slider change, so the footer
only recorded an event and closed the popup. The options panel no longer
passes footer (no empty footer area or divider); reset stays in the title bar.
The 축척 지정 input popup keeps its footer. VIEWER.md §4.1, the composition
pattern and Example H follow.

src/sw/sw-viewer-fixture.tsx

@@ -157,13 +157,13 @@ function SliderRow({ label, unit, value, min, max, step, disabled, onChange }: {
   )
 }
 
-export function OptionsPanel({ demo, footer, ...placement }: { demo: ViewerDemo; footer?: boolean } & PanelPlacement) {
+export function OptionsPanel({ demo, ...placement }: { demo: ViewerDemo } & PanelPlacement) {
   const { options, setOptions } = demo
   const set = (patch: Partial<ViewerOptions>) => setOptions({ ...options, ...patch })
   return (
     <SWViewerPanel title="옵션" open={demo.panels.options} onClose={() => demo.toggle("options", false)} width={340} height={520} {...placement}
-      headerActions={<SWViewerButton variant="ghost" aria-label="기본값으로" title="기본값으로" onClick={() => { setOptions(DEFAULT_OPTIONS); demo.record("options:reset") }}><RotateCcw size={16} /></SWViewerButton>}
-      footer={footer ? <><SWViewerButton onClick={() => demo.toggle("options", false)}>취소</SWViewerButton><SWViewerButton variant="primary" onClick={() => { demo.record("options:apply"); demo.toggle("options", false) }}>적용</SWViewerButton></> : undefined}>
+      headerActions={<SWViewerButton variant="ghost" aria-label="기본값으로" title="기본값으로" onClick={() => { setOptions(DEFAULT_OPTIONS); demo.record("options:reset") }}><RotateCcw size={16} /></SWViewerButton>}>
+      {/* 2026-10-22: no 취소 / 적용 footer — every toggle, input and slider applies at once. */}
       <SWViewerSection title="선가중치">
         {/* 2026-10-22 options image: LWDISPLAY toggle; scale input + px/mm unit on the label row, slider below. */}
         <SWViewerField label="표시 (LWDISPLAY)">{id => <SWViewerSwitch id={id} checked={options.lineweightOn} onCheckedChange={lineweightOn => set({ lineweightOn })} />}</SWViewerField>

src/sw/sw-viewer.stories.tsx

@@ -261,7 +261,7 @@ export const SettingsPanel: Story = {
         <StoryPageHeader kicker={KICKER} title="SW Viewer — 설정창 (SWViewerPanel)" />
         <Log lines={demo.log} />
         <ViewerFrame header={<SWViewerHeader documentTitle={demo.documentName} {...demo.fileProps} groups={demo.groups} trailing={demo.trailing} onCommand={demo.onCommand} />}>
-          <OptionsPanel demo={demo} strategy="absolute" footer />
+          <OptionsPanel demo={demo} strategy="absolute" />
         </ViewerFrame>
       </StoryPage>
     )
@@ -291,7 +291,7 @@ export const ContentVariants: Story = {
               <SWViewerField label="단위">{id => <SWSelect id={id} defaultValue="mm" options={[{ value: "mm" }, { value: "m" }]} onValueChange={value => demo.record(`unit=${value}`)} data-sw-select="unit" />}</SWViewerField>
             </SWViewerSection>
           </SWViewerPanel>
-          <OptionsPanel demo={demo} strategy="absolute" defaultPosition={{ left: 712, top: 16 }} footer />
+          <OptionsPanel demo={demo} strategy="absolute" defaultPosition={{ left: 712, top: 16 }} />
           {!inputOpen && <button type="button" className="sw-viewer-story-reopen" onClick={() => setInputOpen(true)}>축척 지정 다시 열기</button>}
         </ViewerFrame>
       </StoryPage>