feat(chart): add @hm-design/chart package with Bar, Line, Donut, Pie, Radar, Area and Radial charts

- new workspace package packages/chart (shadcn/ui Chart + Recharts, HM Theme tokens), examples entry with sample data
- Storybook Chart group (src/chart), consumer example (examples/chart), build:chart / build:chart-example scripts
- README rewritten as the AI usage guide (install, CSS wiring, chart selection, data rules, verification)
- docs: package count/list, Submodule guide (chart workspace, React dedupe), shared AI_GUIDE row, MAINTAINING, story inventory

examples/chart/main.tsx

@@ -0,0 +1,27 @@
+import { StrictMode } from "react"
+import { createRoot } from "react-dom/client"
+import { AreaStackedExample, ChartExamples, PieLabelExample, RadarPlainExample, RadialTextExample } from "@hm-design/chart/examples"
+import "./index.css"
+import "./hm-theme.css"
+
+// Consumer of the public @hm-design/chart entries only: bar, line and donut sample cards plus one Pie, Radar, Area and Radial example.
+createRoot(document.getElementById("root")!).render(
+  <StrictMode>
+    <div className="chart-example">
+      <main className="chart-example-main">
+        <header>
+          <h1>HMDesign 차트 예제</h1>
+          <p>막대·선·도넛 차트와 파이·방사형(Radar)·영역·래디얼 차트 예시의 표시와 툴팁·범례·반응형 동작을 확인하는 화면입니다. 모든 값은 예시 데이터입니다.</p>
+        </header>
+        <ChartExamples />
+        {/* One example each of the Pie, Radar, Area and Radial charts. */}
+        <div className="grid grid-cols-1 gap-6 lg:grid-cols-2">
+          <PieLabelExample className="min-w-0" />
+          <RadarPlainExample className="min-w-0" />
+          <AreaStackedExample className="min-w-0" />
+          <RadialTextExample className="min-w-0" />
+        </div>
+      </main>
+    </div>
+  </StrictMode>,
+)