feat: add MTR display board and train info components

- Implemented MtrDisplayBoard component to show train schedules with weather information.
- Created MtrTrainInfo component to manage state and render MtrDisplayBoard.
- Added ScreenshotTaker component for downloading screenshots of the display board.
- Introduced theme toggle functionality with ThemeToggle component.
- Developed various UI components including Button, Card, ColorPicker, DropdownMenu, Input, Label, Popover, Select, Separator, Switch, Tabs, and Textarea.
- Added utility functions for class name merging and tool definitions.

src/components/ui/label.tsx

@@ -0,0 +1,24 @@
+"use client"
+
+import * as React from "react"
+import * as LabelPrimitive from "@radix-ui/react-label"
+
+import { cn } from "@/lib/utils"
+
+function Label({
+  className,
+  ...props
+}: React.ComponentProps<typeof LabelPrimitive.Root>) {
+  return (
+    <LabelPrimitive.Root
+      data-slot="label"
+      className={cn(
+        "flex items-center gap-2 text-sm leading-none font-medium select-none group-data-[disabled=true]:pointer-events-none group-data-[disabled=true]:opacity-50 peer-disabled:cursor-not-allowed peer-disabled:opacity-50",
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+export { Label }