docs(debt): record that sceAjmBatchJobGetStatistics only zero-fills its sideband

docs/dev/debt/libSceAjm.native.md

@@ -12,6 +12,7 @@
 - [AJM Opus decoder](../../../core/libs/prx/libSceAjm.native/src/Ajm.cpp) (libSceAjm.native, codec 24) - the initialize parameter layout and little-endian `u16` packet byte count come from The Smurfs Dreams (`2, 48000, 0`) and Lost Soul Aside (`4, 48000, 1`). The third word is interpreted as the mapping family, as in [KytyPS5's initialize structure](https://github.com/KytyPS5/KytyPS5/blob/984cfcebd141b211aa9e0a8cde63b0ebe652d07a/src/libs/ajm/opus_decoder.h#L11-L15). Family 1 uses the conventional stream counts, coupled counts and channel map from [libopus 1.5.2's surround layout](https://github.com/xiph/opus/blob/v1.5.2/src/opus_multistream_encoder.c#L47-L55), passed to FFmpeg through an [RFC 7845 section 5.1](https://datatracker.ietf.org/doc/html/rfc7845#section-5.1) header with zero pre-skip and gain; gapless skipping remains controlled by AJM sideband parameters. FFmpeg returns PCM in its native speaker order. The implicit stream layout, PCM channel order and invalid family-0 channel count result are not verified on a console. NHL 27 (PPSA34063) passes `1, 48000, 255`. Family 255 with one channel is decoded as one mono stream, the same as family 0; this is assumed, since the stream count, coupled stream count and channel mapping that a family-255 Opus header carries ([RFC 7845 section 5.1.1](https://datatracker.ietf.org/doc/html/rfc7845#section-5.1.1)) are not passed. Only 48000 Hz, mapping families 0 and 1, and family 255 with one channel are implemented; other rates and families, and family 255 with more channels, throw
 - [AJM codec 23](../../../core/libs/prx/libSceAjm.native/src/Ajm.cpp) (libSceAjm.native) - taken as interleaved `s16` PCM that only passes through the resampler, from Broken Sword - Shadow of the Templars: Reforged (PPSA21480); no source names a codec 23 ([shadPS4's PS4 header](https://github.com/shadps4-emu/shadPS4/blob/5aa7ffa3f4f21bba827d7865ed8f69f98f993542/src/core/libraries/ajm/ajm.h#L19-L25) ends its codec list with `Max = 23`) and the name `CODEC_PCM` is ours. The title decodes its Ogg Opus and Vorbis audio itself and, for every block, initializes the instance (flags 0x1002) with `0, 2, 44100`, sets the ratio 0.91875 (44100/48000) and decodes 235 stereo frames into a 256-frame output. The 12 initialize bytes are taken as input format (0 is `s16`, other values throw), channel count and sample rate; the rate is only reported in the format sideband; other sizes throw; zero or more than 8 channels or a zero rate return the invalid-parameter result as for Opus, not verified. A run consumes its whole input and emits every output frame whose position (output index × ratio) is below the input frame count, with the 4-point Catmull-Rom of the other codecs' resampler and the first and last input frames repeated past the edges, so each run restarts at position 0; `totalDecodedSamples` counts input frames; `s32` and float outputs are accepted although only `s16` was seen. Throwing because the console's behaviour is unknown: a run after a resampled run without an initialize or context clear in between (whether the console carries the resampler position across runs), a ratio change per sample, gapless counts, an empty input or one that is not a whole number of frames, an output that cannot hold the resampled input, run flags other than `SIDEBAND_STREAM` and initialization through `sceAjmBatchJobControl`
 - [sceAjmBatchJobSetResampleParametersEx](../../../core/libs/prx/libSceAjm.native/src/Ajm.cpp) (libSceAjm.native) - the `(info, instance, float ratio_start, float ratio_change_per_sample, flags, result)` signature is inferred from the name and from `sceAjmBatchJobSetResampleParameters`, and PPSA02225's one call agrees with that layout (`rdi`, `esi`, `xmm0` and `xmm1` as two single floats, `edx`, `rcx`) without showing `flags` or the float roles. With a zero change per sample it sets the ratio as `sceAjmBatchJobSetResampleParameters` does (Watch Dogs: Legion, PPSA01500, calls it so). How a non-zero change ramps the ratio is not confirmed on a console (no source: KytyPS5 ignores it, prosper stubs it, the PS5 firmware does not export the batch builders to a payload): it is assumed to be added to the ratio after each emitted output frame, clamped at zero, and kept across batches. RIDE 4 (PPSA01599) passes one call with a change of 4.6e-7, so the exact rule matters little there.
+- [sceAjmBatchJobGetStatistics](../../../core/libs/prx/libSceAjm.native/src/Ajm.cpp) (libSceAjm.native) - the job zero-fills the first 24 bytes of its sideband and ignores the interval; no source gives this function's result layout or values and no test covers it. [KytyPS5](https://github.com/KytyPS5/KytyPS5/blob/984cfcebd141b211aa9e0a8cde63b0ebe652d07a/src/libs/ajm.cpp#L973-L979) zero-fills a 48-byte result instead (the 8-byte result, a batch engine usage, three interval engine usages and six memory words), and [shadPS4](https://github.com/shadps4-emu/shadPS4/blob/15abf68c9b52c4b04d094f2837719fdb871021f3/src/core/libraries/ajm/ajm.h#L147-L170) (PS4) names engine and memory statistics sidebands but not this builder
 - [sceAjmBatchJobControl](../../../core/libs/prx/libSceAjm.native/src/Ajm.cpp) (libSceAjm.native) - RESET (bit 13), INITIALIZE (bit 14) and the sideband input order (gapless decode, then initialize parameters) come from [shadPS4](https://github.com/shadps4-emu/shadPS4) (PS4); the one call in PPSA25936 passes the flags 0x4000 (bit 14 only), an 8-byte input and an 8-byte output, which agrees with INITIALIZE alone and the 8-byte parameters, without showing the codec or the meaning of the words; other flags throw
 - [sceAjmBatchJobControl](../../../core/libs/prx/libSceAjm.native/src/Ajm.cpp) (libSceAjm.native) - RESET is assumed to clear the context as sceAjmBatchJobClearContext does
 - [sceAjmBatchJobControl](../../../core/libs/prx/libSceAjm.native/src/Ajm.cpp) (libSceAjm.native) - initialize parameters are 8 bytes for ATRAC9 and M4AAC, 12 for Opus and none for MP3, as one title passes them; other codecs and sizes, and an output other than the 8-byte result, throw