fix: mystats username lookup and multi-word name support

- Résolution du nom via find_user_by_name avant get_user_all_pbs
  (l'ancien code passait le nom en guise de discord_id → aucun résultat)
- Affichage du nom de la cible dans le titre de l'embed
- * pour capturer les noms avec espaces

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cogs/mystats.py

@@ -12,21 +12,33 @@ class MyStats(commands.Cog):
         self.bot = bot
 
     @commands.command(name="mystats")
-    async def mystats(self, ctx, target_user: str = None):
+    async def mystats(self, ctx, *, target_user: str = None):
         """Affiche tous les PB d'un utilisateur avec les nouvelles difficultés"""
         if ctx.channel.id != AUTHORIZED_CHANNEL_ID:
             return
 
         try:
-            username = target_user if target_user else ctx.author.id
-            user_data = db_manager.get_user_all_pbs(username)
+            if target_user:
+                matches = db_manager.find_user_by_name(target_user)
+                if not matches:
+                    await ctx.send(f"❌ No data found for **{target_user}**.")
+                    return
+                if len(matches) > 1:
+                    await ctx.send(f"⚠️ Multiple users found for **{target_user}**. Please be more specific.")
+                    return
+                user_id, display_name = matches[0]
+            else:
+                user_id = ctx.author.id
+                display_name = ctx.author.display_name
+
+            user_data = db_manager.get_user_all_pbs(user_id)
 
             if not user_data:
-                await ctx.send(f"❌ No data found for **{ctx.author.display_name}**.")
+                await ctx.send(f"❌ No data found for **{display_name}**.")
                 return
 
             embed = discord.Embed(
-                title=f"📊 {ctx.author.display_name}'s Complete Stats",
+                title=f"📊 {display_name}'s Complete Stats",
                 color=0x00bfff
             )