feat(sw): viewer mode header, dropdown and popup panel

- SWViewerHeader: data-driven viewer menu (button / toggle / menu / tabs / switch / custom), More by
  collapseBelow, trailing slot, onCommand; SWHeader logo props with no default logo
- SWViewerMenu: dropdown, check / radio, multi-level submenu, context menu at a point
- SWViewerPanel: viewer popup frame with free children / footer, drag, corner resize, collapse, modal
- Panel controls: SWViewerSection / Field / Hint / Switch / Slider / Input / Button / Badge / Status
- SWHeader black text outline tokens on viewer text, matching icon outline (drop-shadow)
- Storybook SW/Viewer stories; remove SW/Tool story (SW/Popup kept)
- AI guide ai/VIEWER.md, example H, verification scripts and evidence

packages/sw/tests/storybook-inventory.mjs

@@ -14,6 +14,9 @@ export const inventorySignature = entries => entries.map(entry => [entry.id, ent
 // SW/Header next to its 10 retained Stories, the rest under SW/Tool and SW/Popup), and the only package files it changed.
 // The two Header Stories sit directly under SW/Header (no separate Options menu), in src/sw/sw-header-open.stories.tsx.
 export const integratedStoryIds = ['sw-header--document-open', 'sw-header--hidden-sub-controls', 'sw-tool--tool-buttons', 'sw-popup--custom-content', 'sw-popup--multiple-popups']
+// 2026-10-19 (viewer worktree, user request): the SW/Tool Story menu was removed; SW/Popup (the common SWPopup
+// examples) stays. SWToolButton / SWToolGroup stay public; integrated-improvement.browser.mjs opening this id is historical evidence only.
+export const retiredToolIds = ["sw-tool--tool-buttons"]
 export const integratedChangedFiles = [
   'packages/sw/README.md', 'packages/sw/package.json', 'packages/sw/build.mjs',
   'packages/sw/ai/AI_USAGE.md', 'packages/sw/ai/COMPONENT_CATALOG.md', 'packages/sw/ai/COMPOSITION_PATTERNS.md', 'packages/sw/ai/DESIGN_RULES.md',