Recreate Next.js source — shadcn components, chart, types, hooks

Source files were untracked and lost during reset. Recreated:
- page.tsx (full 3-tab dashboard), layout.tsx, globals.css (shadcn theme)
- types.ts, api.ts, utils.ts
- strategy-card.tsx, equity-chart.tsx, positions-panel.tsx
- ui/ (7 shadcn wrappers: card, badge, button, table, tabs, sheet, collapsible, select)
- Config files: next.config.ts, tsconfig.json, postcss.config.mjs, components.json

dashboard-next/components.json

@@ -0,0 +1,21 @@
+{
+  "$schema": "https://ui.shadcn.com/schema.json",
+  "style": "new-york",
+  "rsc": true,
+  "tsx": true,
+  "tailwind": {
+    "config": "",
+    "css": "src/app/globals.css",
+    "baseColor": "slate",
+    "cssVariables": true,
+    "prefix": ""
+  },
+  "iconLibrary": "lucide",
+  "aliases": {
+    "components": "@/components",
+    "utils": "@/lib/utils",
+    "ui": "@/components/ui",
+    "lib": "@/lib",
+    "hooks": "@/hooks"
+  }
+}