Default sentiment backend — lexicon-based, multilingual via the bundled AFINN lexicons.
This module implements the Text.Sentiment.Backend behaviour by
wrapping Text.Sentiment.Lexicon.score/3, picking the bundled
Text.Sentiment.Lexicons.AFINN lexicon that matches the supplied
:language option (with fallback to :en).
Most callers don't reference this module directly — they go through
Text.Sentiment.analyze/2 or label/2, which dispatch via
Text.Sentiment.Backend.resolve/1.