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/src/components/ui/select.tsx

@@ -0,0 +1,26 @@
+"use client";
+
+import * as React from "react";
+import { cn } from "@/lib/utils";
+import { ChevronDown } from "lucide-react";
+
+function Select({ value, onChange, className, children, ...props }: React.ComponentProps<"select"> & { onChange?: (e: React.ChangeEvent<HTMLSelectElement>) => void }) {
+  return (
+    <select
+      data-slot="select"
+      value={value}
+      onChange={onChange}
+      className={cn(
+        "border-input file:text-foreground placeholder:text-muted-foreground selection:bg-primary selection:text-primary-foreground flex h-9 w-full rounded-md border bg-transparent px-3 py-1 text-base shadow-xs transition-[color,box-shadow] outline-none file:inline-flex file:h-7 file:border-0 file:bg-transparent file:text-sm file:font-medium disabled:pointer-events-none disabled:cursor-not-allowed disabled:opacity-50 md:text-sm",
+        "focus-visible:border-ring focus-visible:ring-ring/50 focus-visible:ring-[3px]",
+        "aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive",
+        className,
+      )}
+      {...props}
+    >
+      {children}
+    </select>
+  );
+}
+
+export { Select };