### wai.h holds the C interface alone

- **`wai-rs/include/wai.h`**: `build.rs` hands cbindgen the four files of the C interface,
  `src/ffi.rs`, `src/ffi_codecs.rs`, `src/ffi_neural.rs` and `src/ffi_sink.rs`, and nothing else of
  the crate, so the header declares the `wai_*` functions, the `WAI_*` constants and the `wai_*_t`
  types those files define, and nothing more. Read from the whole crate, it carried every public
  constant of every module as a macro, some names several times over with one value each, and an
  opaque typedef for each type such a constant belongs to. No `wai_*` or `WAI_*` declaration
  changed. `quickstart/libwai_interface.py`, run with the repository checks, holds the committed
  header to that: every macro `WAI_*`, every type `wai_*`, a declaration for each export of the four
  files and none other.
- **Breaking:** the header no longer declares the crate's other constants and types, none of which
  the C interface takes or returns; a C program that named one gave its own meaning to an internal
  value, and states the number it needs itself: `api:c:A`, `api:c:ADD_FIXED`, `api:c:ADD_INT`,
  `api:c:AUDIO_DECODED_MAX_SAMPLES`, `api:c:AV1_DECODE_DEFAULT_MAX_LEN`, `api:c:CHAIN_HELD_LINKS`,
  `api:c:CLIP_FRAMES`, `api:c:CLIP_SIDE`, `api:c:CREATE`, `api:c:CREATE_MEMBER`,
  `api:c:CREATE_PARTICLE`, `api:c:DELETE`, `api:c:F`, `api:c:Fx_FRAC_BITS`, `api:c:HEAD`,
  `api:c:HeadProof_FIXED_LEN`, `api:c:HeadProof_MAX_CV`, `api:c:IMAGE_MAX_PIXELS`,
  `api:c:IMAGE_MAX_SIDE`, `api:c:IMPULSE`, `api:c:LoadedSets_DEFAULT_BUDGET`,
  `api:c:LoadedSets_INDEX_BYTES_PER_ENTRY`, `api:c:MANIFEST_MAX_LEN`, `api:c:MANIFEST_MAX_VALUES`,
  `api:c:MARKER_EOC`, `api:c:MARKER_PIH`, `api:c:MARKER_RDI`, `api:c:MARKER_SOC`,
  `api:c:MARKER_SOQ`, `api:c:MARKER_SORP`, `api:c:MARKER_SORS`, `api:c:MARKER_SOZ`,
  `api:c:MARKER_TON`, `api:c:MARKER_UDI`, `api:c:MAX_CAPS`, `api:c:MAX_EMBEDDED`,
  `api:c:MAX_EVIDENCE`, `api:c:MAX_PERIODS`, `api:c:MAX_STEPS`, `api:c:MAX_STRING`,
  `api:c:MAX_TRACKS`, `api:c:MUT_ACTION`, `api:c:NOISE`, `api:c:PERIOD_MAX_LAG`,
  `api:c:PERIOD_MEDIANS`, `api:c:PERIOD_SAMPLE`, `api:c:PERIOD_Z`, `api:c:PIECE_KIND_NONE`,
  `api:c:PROB_FRAC`, `api:c:PULSE25`, `api:c:PULSE25_BL`, `api:c:REGISTER_DELTA_UNCERTAINTY_UJ`,
  `api:c:RENDER_MAX_FRAMES`, `api:c:RENDER_MAX_SAMPLES`, `api:c:RESOLUTION_FLOOR_UJ_PPM`,
  `api:c:RESOLUTION_UNCERTAINTY_UJ`, `api:c:S`, `api:c:SAW`, `api:c:SAW_BL`, `api:c:SCALE_FRAC`,
  `api:c:SCAN`, `api:c:SECTION_ASSETS`, `api:c:SECTION_CONTRACT`, `api:c:SECTION_GRAPH`,
  `api:c:SECTION_OPLOG`, `api:c:SECTION_SEAL`, `api:c:SEGMENT_SAMPLES`, `api:c:SET_CELL`,
  `api:c:SET_POS`, `api:c:SET_ROTATION`, `api:c:SET_SCALAR`, `api:c:SET_SCALE`, `api:c:SET_SIDE`,
  `api:c:SET_SIZE`, `api:c:SET_TRANSLATION`, `api:c:SINE`, `api:c:SQUARE`, `api:c:SQUARE_BL`,
  `api:c:TEXT_DECODED_MAX_LEN`, `api:c:TEXT_WINDOW_MAX_LEN`, `api:c:TEXT_WINDOW_MAX_LOG`,
  `api:c:TRIANGLE`, `api:c:TRITS_PER_BYTE`, `api:c:UNIFORM_SUM`, `api:c:VIDEO_MAX_TEMPORAL_UNITS`,
  `api:c:VOICE_BYTES`, `api:c:Voice_MAX_CURVE`, `api:c:Voice_MAX_ECHO_DELAY`,
  `api:c:Voice_MAX_POLES`, `api:c:Voice_MAX_TAPS`, `api:c:WEFT_ADMITTED_MODES`,
  `api:c:WEFT_LAST_ALLOCATED_MODE`, `api:c:WEFT_MODE_FLOAT_TENSOR`, `api:c:WEFT_MODE_RAW`,
  `api:c:WEFT_MODE_TENSOR`, `api:c:WINDOW`; and the opaque types `api:c:Fx`, `api:c:Isa`,
  `api:c:Plant`, `api:c:PowerSource`, `api:c:Reason`, `api:c:Voice`.