fix(web): tool-call checkmarks nearly invisible on the terracotta (light) theme

text-success/50 and /60 washed out to almost nothing against the light
theme's cream card background — full-opacity text-success still reads
as a calm, muted green (not alarming) but is actually visible on both
themes.

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

web/src/lib/components/ChatThread.svelte

@@ -241,7 +241,7 @@
                 </div>
               {/if}
               {#if idx === messages.length - 1 && msg.text === '' && (streaming || indicatorDone || error)}
-                <div class="flex items-center gap-2 py-1 text-xs {error ? 'text-destructive' : indicatorDone ? 'text-success/50' : 'text-muted-foreground'}">
+                <div class="flex items-center gap-2 py-1 text-xs {error ? 'text-destructive' : indicatorDone ? 'text-success' : 'text-muted-foreground'}">
                   {#if error}
                     <XIcon class="size-3 shrink-0" />
                   {:else if indicatorDone}

web/src/lib/components/ToolCallCard.svelte

@@ -14,7 +14,7 @@
   const statusColor = $derived.by(() => {
     if (status === 'running') return 'text-primary'
     if (status === 'error') return 'text-destructive'
-    return 'text-success/60'
+    return 'text-success'
   })
 
   const argsSummary = $derived.by(() => {