Add a "Send IRC Message" section to the admin dashboard that sends a
configurable privmsg to any IRC nick or channel via all connected bots.
New POST /admin/ping endpoint broadcasts a "privmsg" WebSocket message
type, handled by both Limnoria and Sopel plugins.
Also enable pydantic-settings .env file loading (python-dotenv) and
add .env.example documenting all NTR_* configuration variables.
Made-with: Cursor
Decouple the like-window boundary (Wed 10pm ET) from when the system
rotates to a new show. NTR_SHOW_ROTATION_DELAY_HOURS=2 keeps the
previous week's show visible during the ~2 hour recording, then creates
the new show at midnight.
Made-with: Cursor
