make the jobs back button a link, delete the backbutton nobody used

The audit said adopt the shared BackButton. It is not shared: zero importers
since the initial commit, no barrel entry, and a label-plus-underline shape
that fits none of the icon-only back controls here. Adopting it would have
redesigned the Jobs header under cover of a navigation fix.

So: a Link, matching what ScriptJobDetail and DownloadJobDetail already do,
and the dead component goes. useNavigate had no other caller in
PipelineJobDetail and goes with it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/apps/officer-web/Screens/Dashboard/Jobs/JobDetail.tsx

@@ -1,5 +1,5 @@
 import { useState, useEffect, useRef, useCallback, useMemo, createContext, useContext } from 'react';
-import { useParams, useNavigate, Link } from 'react-router';
+import { useParams, Link } from 'react-router';
 import {
   ArrowLeft, CheckCircle2, AlertCircle, Loader2, StopCircle, AlertTriangle, Clock, Square,
   ChevronRight, Wrench,
@@ -332,7 +332,6 @@ const OutputPanel = () => {
 
 export const PipelineJobDetail = () => {
   const { id } = useParams<{ id: string }>();
-  const navigate = useNavigate();
   const client = useClient();
 
   const [job, setJob] = useState<JobData | null>(null);
@@ -706,9 +705,10 @@ export const PipelineJobDetail = () => {
       {/* Header + stats bar */}
       <Card className="px-4 py-3 shrink-0">
         <div className="flex items-center gap-3">
-          <button onClick={() => navigate('/jobs')} className="p-1 rounded hover:bg-duck-dark/10 cursor-pointer">
+          {/* The other two job detail panes already do this; this was the last imperative back in Jobs. */}
+          <Link to="/jobs" aria-label="Back to jobs" className="p-1 rounded hover:bg-duck-dark/10 cursor-pointer">
             <ArrowLeft className="h-4 w-4 text-duck-dark/60" />
-          </button>
+          </Link>
           <div className="flex-1 min-w-0">
             <div className="flex items-center gap-2">
               <StatusIcon status={displayStatus} className="h-5 w-5" />

src/workspaces/components/BackButton.tsx

@@ -1,13 +0,0 @@
-import { Link } from 'react-router';
-import { ArrowLeft } from 'lucide-react';
-import { cn } from 'helpers/cn';
-
-type BackButtonProps = { label: string; href: string; className?: string };
-export const BackButton = ({ label, href, className }: BackButtonProps) => {
-  return (
-    <Link to={href} className={cn('flex items-center text-lg text-gray-600 underline dark:text-gray-300', className)}>
-      <ArrowLeft className="mr-1 h-4 w-4" />
-      {label}
-    </Link>
-  );
-};