52c5ca7ce5
Replaces hand-written reduce_threads=512, reduce_items=16 with
_read_reduce_config(accum_size) that reads from tuning_reduce.cuh
via gen_patch.extract_bi100_structs().
Architecture change:
OLD: hand-write values in Python + verify_against_headers() asserts equal
NEW: _read_reduce_config() reads from C++ header (single source of truth)
Falls back to compiled-in defaults only when headers not on disk
(deployed container), with RuntimeWarning.
No hand-written tuning values remain in the normal code path.
verify_against_headers() removed — there is nothing to verify
when there is only one copy of the truth.