refactor: add leveling view layer

Create leveling.view.ts with UI logic extracted from leaderboard command:
- getLeaderboardEmbed() for leaderboard display (XP and Balance)
- getMedalEmoji() helper for ranking medals (🥇🥈🥉)
- formatLeaderEntry() helper for entry formatting with null safety

Updated leaderboard.ts to use view functions instead of inline formatting.

src/commands/leveling/leaderboard.ts

@@ -3,7 +3,8 @@ import { SlashCommandBuilder } from "discord.js";
 import { DrizzleClient } from "@/lib/DrizzleClient";
 import { users } from "@/db/schema";
 import { desc } from "drizzle-orm";
-import { createWarningEmbed, createBaseEmbed } from "@lib/embeds";
+import { createWarningEmbed } from "@lib/embeds";
+import { getLeaderboardEmbed } from "@/modules/leveling/leveling.view";
 
 export const leaderboard = createCommand({
     data: new SlashCommandBuilder()
@@ -34,13 +35,7 @@ export const leaderboard = createCommand({
             return;
         }
 
-        const description = leaders.map((user, index) => {
-            const medal = index === 0 ? "🥇" : index === 1 ? "🥈" : index === 2 ? "🥉" : `${index + 1}.`;
-            const value = isXp ? `Lvl ${user.level} (${user.xp} XP)` : `${user.balance} 🪙`;
-            return `${medal} **${user.username}** — ${value}`;
-        }).join("\n");
-
-        const embed = createBaseEmbed(isXp ? "🏆 XP Leaderboard" : "💰 Richest Players", description, "Gold");
+        const embed = getLeaderboardEmbed(leaders, isXp ? 'xp' : 'balance');
 
         await interaction.editReply({ embeds: [embed] });
     }