feat: add K/M/B/T cost shortener to prevent UI overflow (#1902)

Integrated into release/v3.7.9

src/shared/utils/formatting.ts

@@ -146,6 +146,55 @@ export function formatCost(usd: number | null | undefined): string {
 
 export const fmtCost = formatCost;
 
+/**
+ * Format a USD cost for display using abbreviated K/M/B/T suffixes.
+ * Sub-cent values show additional precision.
+ *   - Values >= 1T are shown as $X.XT
+ *   - Values >= 1B are shown as $X.XB
+ *   - Values >= 1M are shown as $X.XM
+ *   - Values >= 1K are shown as $X.XK
+ *   - Otherwise shown as $X.XX
+ * @param {number} usd - Cost in USD
+ * @returns {string}
+ */
+export function formatCostAbbreviated(usd: number | null | undefined): string {
+  const value = Number(usd || 0);
+  if (!Number.isFinite(value) || value === 0) return "$0";
+  const abs = Math.abs(value);
+  if (abs < 0.01) {
+    if (value < 0) {
+      return `-$${Math.abs(value).toFixed(6)}`;
+    }
+    return `$${value.toFixed(6)}`;
+  }
+  let divisor: number, suffix: string;
+  if (abs >= 1_000_000_000_000) {
+    divisor = 1_000_000_000_000;
+    suffix = "T";
+  } else if (abs >= 1_000_000_000) {
+    divisor = 1_000_000_000;
+    suffix = "B";
+  } else if (abs >= 1_000_000) {
+    divisor = 1_000_000;
+    suffix = "M";
+  } else if (abs >= 1_000) {
+    divisor = 1_000;
+    suffix = "K";
+  } else {
+    if (value < 0) {
+      return `-$${Math.abs(value).toFixed(2)}`;
+    }
+    return `$${value.toFixed(2)}`;
+  }
+  const abbreviated = abs / divisor;
+  let formatted = abbreviated.toFixed(1);
+  if (formatted.includes(".")) {
+    formatted = formatted.replace(/\.?0+$/, "");
+  }
+  const sign = value < 0 ? "-" : "";
+  return `${sign}$${formatted}${suffix}`;
+}
+
 /**
  * Truncate a URL for compact display.
  * @param {string} url - Full URL