feat: Implement a new terminal dashboard featuring an analytics panel, sparklines, and foundational UI components and utilities.

frontend/lib/utils.ts

@@ -0,0 +1,49 @@
+import { type ClassValue, clsx } from "clsx";
+import { twMerge } from "tailwind-merge";
+
+/**
+ * Utility for merging tailwind classes safely.
+ */
+export function cn(...inputs: ClassValue[]) {
+  return twMerge(clsx(inputs));
+}
+
+/**
+ * Formats a number as a currency string.
+ */
+export function formatCurrency(value: number, decimals: number = 2) {
+  return new Intl.NumberFormat("en-US", {
+    style: "currency",
+    currency: "USD",
+    minimumFractionDigits: decimals,
+    maximumFractionDigits: decimals,
+  }).format(value);
+}
+
+/**
+ * Formats a percentage from midpoint.
+ */
+export function formatPercent(value: number) {
+  return (value * 100).toFixed(1) + "%";
+}
+
+/**
+ * Converts Fahrenheit to Celsius.
+ */
+export function fToC(f: number) {
+  return ((f - 32) * 5) / 9;
+}
+
+/**
+ * Formats a date/time string to HH:MM:SS.
+ */
+export function formatTime(date: Date | string) {
+  const d = typeof date === "string" ? new Date(date) : date;
+  if (isNaN(d.getTime())) return String(date);
+  return d.toLocaleTimeString("zh-CN", {
+    hour12: false,
+    hour: "2-digit",
+    minute: "2-digit",
+    second: "2-digit",
+  });
+}