fix: merge duplicate time-utils imports in human.ts

Consolidate two separate imports from time-utils.js into a single
import statement at the top of the file. Removes the mid-file import
that was left from the circular import refactor.

Author: BYK

src/lib/formatters/human.ts

@@ -39,7 +39,7 @@ import {
 } from "./markdown.js";
 import { sparkline } from "./sparkline.js";
 import { type Column, writeTable } from "./table.js";
-import { computeSpanDurationMs } from "./time-utils.js";
+import { computeSpanDurationMs, formatRelativeTime } from "./time-utils.js";
 
 // Color tag maps
 
@@ -200,9 +200,6 @@ export function formatStatusLabel(status: string | undefined): string {
   );
 }
 
-// formatRelativeTime moved to time-utils.ts to break circular import
-import { formatRelativeTime } from "./time-utils.js";
-
 // Issue Formatting
 
 /** Quantifier suffixes indexed by groups of 3 digits (K=10^3, M=10^6, …, E=10^18) */