Episode gains an additive absolute field services can set, an {absolute}
naming token (3-wide), and an --enrich fill from TVDB's absolute order
that never rewrites season or episode numbers.
Document tvdb_api_key, tvdb_pin, tvdb_order and metadata_providers, the
--tvdb and --tvdb-order flags with their behaviour when an order does
not cover a whole series, the new REST API parameters, and the Matroska
TVDB2 tag prefixes.
Detect the dot/space style from the full folder template instead of per segment, so `{artist}/{album} ({year})` no longer yields `Some.Artist/Some Album (2025)`. Also drops empty `[]` groups like the existing `()` handling and removes redundant cleanup passes.
imSp4rky