Replace keyboard emojis with the app's own lucide icons (quiz reactions, +XP, welcome hand, party popper, streak flame)

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

src/screens/LessonsScreen.tsx

@@ -1,6 +1,6 @@
 import { useState } from 'react';
 import { motion } from 'motion/react';
-import { Brain, Check, ChevronDown, Lock, Play, Sparkles } from 'lucide-react';
+import { Brain, Check, ChevronDown, Lock, PartyPopper, Play, Sparkles } from 'lucide-react';
 import { api, type HomeNode, type HomeUnit } from '@/api';
 import { useAppData } from '@/state/AppData';
 import { findContinue, unitColor, unitProgress } from '@/state/curriculum';
@@ -132,7 +132,7 @@ function UnitCard({
         </span>
         <span className="min-w-0 flex-1">
           <span className="block text-[11px] font-bold" style={{ color }}>
-            {complete ? 'تموم شد 🎉' : `${toFa(p.total)} جزیره`}
+            {complete ? <><PartyPopper size={12} className="mb-0.5 ml-1 inline" />تموم شد</> : `${toFa(p.total)} جزیره`}
           </span>
           <span className="block text-sm font-black leading-6 text-ink"><MathText text={unit.title} /></span>
           <span className="mt-1 flex items-center gap-2">