Function prefill_batched_first_chunk_enabled 

pub fn prefill_batched_first_chunk_enabled() -> bool

Whether chunk-zero streams may use the paged batched-prefill path.

★ THE OR MUST SURVIVE THE PROMOTION. In THIS crate codispatch is one of TWO ways to enable the same path, OR-ed with the older AVAROK_Q12_BATCHED_FIRST_CHUNK spelling; in spark-server it is a standalone scheduling switch. A 1:1 replacement of the env read here would have silently dropped the Q12 alias and turned a path off for recipes that still set it. The two meanings are why this reads as an explicit OR rather than sharing the scheduler’s call.