docs(storybook): simplify sidebar Story pages around the UI

Drop the category kicker from the 83 sidebar Stories (kicker is now optional;
hidden verification Stories keep it) and shorten or remove repeated, obvious
or internal page/section descriptions. Required specs, limits, virtual-data
and undecided-value notices stay. Story IDs, exports, fixtures, shared state
notes and package code are unchanged. Record: docs/reports/storybook-ui-simplification-2026-10-22.md

src/components/checkbox.stories.tsx

@@ -2,7 +2,7 @@ import { useId, useState, type ReactNode } from "react"
 import type { Meta, StoryObj } from "@storybook/react-vite"
 import { Checkbox, Label } from "@hm-design/ui"
 import { StateBoard } from "@/components/story-board"
-import { STORY_KICKER, StoryPage, StoryPageHeader, StorySection } from "@/components/story-page"
+import { StoryPage, StoryPageHeader, StorySection } from "@/components/story-page"
 
 // Current HM Checkbox. ui-viz has no Checkbox spec, so it was reference only.
 // The option label is the HM Label; its foreground role for Checkbox options is still TBD in ui_viz.
@@ -48,9 +48,8 @@ export const All: Story = {
   render: () => (
     <StoryPage>
       <StoryPageHeader
-        kicker={STORY_KICKER.components}
         title="Checkbox"
-        description="항목을 선택하거나 해제하는 컨트롤입니다. 18px 박스이며 Checked·Indeterminate는 state-active 색입니다."
+        description="18px 박스 · Checked·Indeterminate는 state-active 색"
       />
       <StorySection title="Overview">
         <StateBoard
@@ -82,7 +81,7 @@ export const All: Story = {
           ]}
         />
       </StorySection>
-      <StorySection title="Validation" description="aria-invalid로 Error 테두리를 표시합니다.">
+      <StorySection title="Validation" description="aria-invalid → Error 테두리">
         <StateBoard min={240} states={[{ id: "error", label: "Error", children: <Option label="Option">{(id) => <Checkbox id={id} aria-invalid />}</Option> }]} />
       </StorySection>
       <StorySection title="Usage">