fix(web): admin error lines use text-error-fg, not the untokened text-oxblood (#5417)

text-oxblood is not a theme token, so Tailwind emits nothing and the scan
error on Admin → Overview and "It stopped early" on Duplicates rendered as
body text. Same fix as the album page in #5392; no uses remain.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/routes/admin/+page.svelte

@@ -428,7 +428,7 @@
       <div class="mt-3 text-xs text-text-muted">
         Started {formatTime(scan.started_at)}
         {#if scan.finished_at}· Finished {formatTime(scan.finished_at)}{/if}
-        {#if scan.error_message}· <span class="text-oxblood">Error: {scan.error_message}</span>{/if}
+        {#if scan.error_message}· <span class="text-error-fg">Error: {scan.error_message}</span>{/if}
       </div>
     {/if}
 

web/src/routes/admin/duplicates/+page.svelte

@@ -191,7 +191,7 @@
         Last swept {relativeTime(sweep.finished_at ?? '')}, comparing
         {(sweep.candidates ?? 0).toLocaleString()} tracks.
         {#if sweep.error_message}
-          <span class="text-oxblood">It stopped early: {sweep.error_message}</span>
+          <span class="text-error-fg">It stopped early: {sweep.error_message}</span>
         {/if}
       {/if}
       {#if prints && prints.pending > 0}