feat: replace orange-* Tailwind classes with blue-* equivalents

orange-400→blue-400, orange-500→blue-500, orange-600→blue-600
across ~21 component files.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/assistant/ConcludeSessionModal.tsx

@@ -467,7 +467,7 @@ export function ConcludeSessionModal({
               {/* Paused/Escalated: generating spinner */}
               {(outcome === 'paused' || outcome === 'escalated') && generatingUpdate && (
                 <div className="flex flex-col items-center justify-center py-8 gap-3">
-                  <Loader2 size={24} className="animate-spin text-orange-400" />
+                  <Loader2 size={24} className="animate-spin text-blue-400" />
                   <p className="text-sm text-muted-foreground">Generating status update...</p>
                 </div>
               )}