v1.5.0 — IPTV + non-YouTube playback

Added

• IPTV (/iptv <name>) — search 50 000+ live TV channels from the iptv-org public catalogue and stream them live; channel logo shown when playing. /iptv with no args shows links to browse channels by country/category. Works in forum groups (posts to the correct topic).
• Non-YouTube URL support in /play and /vplay — Rutube, Vimeo, and any other yt-dlp-supported site now work by extracting the stream URL and feeding it live to ffmpeg (no multi-GB download wait). YouTube continues to download first as before.

Fixed

• ytsearch() no longer tries to do a YouTube keyword search when given a direct URL from a non-YouTube site (was returning "no results found").
• callback.py was missing the can_manage_vc import (undefined name, F821).
• Unused global admins declaration removed from admins.py (F824).