Modernize Discord bot to v14 and Node.js 22

Major upgrades and architectural improvements:
- Upgrade Discord.js from v12 to v14.21.0
- Upgrade Node.js from 14 to 22 LTS
- Switch to pnpm package manager
- Complete rewrite with modern Discord API patterns

New Features:
- Hybrid command system: prefix commands + slash commands
- /sfx slash command with autocomplete for sound discovery
- Modern @discordjs/voice integration for audio
- Improved voice connection management
- Enhanced logging for SFX commands
- Multi-stage Docker build for optimized images

Technical Improvements:
- Modular architecture with services and command handlers
- Proper intent management for Discord gateway
- Better error handling and logging
- Hot-reload capability maintained
- Environment variable support
- Optimized Docker container with Alpine Linux

Breaking Changes:
- Moved main entry from index.js to src/index.js
- Updated configuration structure for v14 compatibility
- Replaced deprecated voice APIs with @discordjs/voice
- Updated audio dependencies (opus, ffmpeg)

🤖 Generated with [Claude Code](https://claude.ai/code)

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

src/commands/slash/sfx.js

@@ -0,0 +1,108 @@
+const { SlashCommandBuilder } = require('discord.js');
+const sfxManager = require('../../services/sfxManager');
+const voiceService = require('../../services/voiceService');
+
+module.exports = {
+  data: new SlashCommandBuilder()
+    .setName('sfx')
+    .setDescription('Play a sound effect')
+    .addStringOption(option =>
+      option.setName('sound')
+        .setDescription('The sound effect to play')
+        .setRequired(true)
+        .setAutocomplete(true)
+    ),
+
+  async execute(interaction, guildConfig) {
+    // Check if SFX is allowed in this channel
+    if (guildConfig.allowedSfxChannels) {
+      const allowedChannels = new RegExp(guildConfig.allowedSfxChannels);
+      if (!allowedChannels.test(interaction.channel.name)) {
+        return interaction.reply({ 
+          content: 'Sound effects are not allowed in this channel!', 
+          ephemeral: true 
+        });
+      }
+    }
+
+    const sfxName = interaction.options.getString('sound');
+    
+    // Log the slash command SFX request
+    console.log(
+      `/sfx '${sfxName}' requested in ${guildConfig.internalName || interaction.guild.name}#${interaction.channel.name} from @${interaction.user.username}`
+    );
+
+    // Check if SFX exists
+    if (!sfxManager.hasSFX(sfxName)) {
+      return interaction.reply({ 
+        content: 'This sound effect does not exist!', 
+        ephemeral: true 
+      });
+    }
+
+    // Check if user is in a voice channel
+    const member = interaction.member;
+    if (!member.voice.channel) {
+      return interaction.reply({ 
+        content: 'You need to be in a voice channel to use this command!', 
+        ephemeral: true 
+      });
+    }
+
+    // Defer the reply as joining voice might take a moment
+    await interaction.deferReply();
+
+    try {
+      // Join the voice channel
+      await voiceService.join(member.voice.channel);
+
+      // Get the SFX file path
+      const sfxPath = sfxManager.getSFXPath(sfxName);
+
+      // Play the sound effect
+      await voiceService.play(
+        interaction.guild.id, 
+        sfxPath, 
+        { 
+          volume: guildConfig.sfxVolume || 0.5 
+        }
+      );
+
+      // Update the reply
+      await interaction.editReply(`Playing sound effect: **${sfxName}**`);
+
+      // Leave the voice channel after playing
+      setTimeout(() => {
+        voiceService.leave(interaction.guild.id);
+      }, 500);
+      
+      console.log(`✅ Successfully played /sfx '${sfxName}'`);
+
+    } catch (error) {
+      console.error(`❌ Error playing /sfx '${sfxName}':`, error);
+      await interaction.editReply({
+        content: "I couldn't play that sound effect. Make sure I have permission to join your voice channel!"
+      });
+    }
+  },
+
+  async autocomplete(interaction, guildConfig) {
+    const focusedValue = interaction.options.getFocused().toLowerCase();
+    
+    // Get all SFX names
+    const choices = sfxManager.getSFXNames();
+    
+    // Filter based on what the user has typed
+    const filtered = choices
+      .filter(choice => choice.toLowerCase().includes(focusedValue))
+      .slice(0, 25); // Discord limits autocomplete to 25 choices
+
+    // Respond with the filtered choices
+    await interaction.respond(
+      filtered.map(choice => ({ 
+        name: choice, 
+        value: choice 
+      }))
+    );
+  }
+};