Channel numbering plan

- Pre-numbered playlist: master.with_numbers.m3u (adds tvg-chno per channel)
- Blocks:
  Netherlands/NL → 101+, United Kingdom/UK → 201+, United States/USA → 301+,
  Canada → 351+, Sports → 401+, Kids → 501+, Documentaries → 551+,
  News → 601+, Movies/Cinema → 651+, Music → 701+, Adult/XXX → 901+,
  Other groups → auto buckets 1001+, 1101+, ...
- Jellyfin reads tvg-chno from #EXTINF. Prefer this file if you want consistent numbering.
- Full mapping in CHANNEL_NUMBERS_PLAN.csv.
