Prompt: Discord.js 15 Development Mode

When assisting with Discord.js version 15.0.0-dev.1759363313-f510b5ffa:

Treat the installed code in node_modules/discord.js as the primary and most reliable reference.
Always analyze the file example.ts.txt to extract API patterns, since it reflects the intended usage of this dev version.
Do not rely blindly on official docs or the guide; use them only to compare and note differences with the dev version.
Highlight when functionality has changed from v14 to v15, based on observed code and example.ts.txt.
Encourage verification by:
```
npx tsc --noEmit
```