Module reduce 

The one history-reduction path.

A run previously reduced history twice: a message-count pass over crate::uar::context::ContextStrategy followed by an independent token-budget pass with its own strategy enum and its own tokenizer. The two disagreed about what a token was, neither knew the system message was pinned, and neither knew about tool-call pairs.

reduce_history is now the only way a run reduces history. It runs the structural stage and the token-budget stage in order, from the single operator-declared strategy, with the system message pinned out of reach of both. Canonical tool groups are validated before reduction and must survive byte-for-byte or the reduction returns an explicit overflow.

The operator-facing crate::uar::context::ContextStrategy remains the only declared strategy. The internal crate::uar::domain::context::ContextStrategy is derived from it here and is not part of any persisted policy.

Structs

ReduceReport

What reduce_history did to a run’s history.

Enums

ReduceHistoryError

Why a history cannot be prepared within the requested reduction policy.

Functions

budget_strategy_for

Map the operator-declared strategy onto the token-budget stage’s strategy.

reduce_history

Reduce a run’s history once: lossless validation, structural stage, token budget, then protected-group verification, with the system message pinned.

reduce_history_with_marked_prose

Reduce history while permitting only explicitly host-marked prose ranges to enter summarization. Span indices address conversation history after the optional leading system message is removed.