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/index.html

@@ -0,0 +1,2 @@
+<!doctype html>
+<html lang="ko"><head><meta charset="UTF-8" /><meta name="viewport" content="width=device-width, initial-scale=1.0" /><title>HMDesign 차트 예제</title><link rel="icon" href="data:," /></head><body><div id="root"></div><script type="module" src="./main.tsx"></script></body></html>