fix(libSceAjm.native): reject a null batch buffer list with a nonzero count

[klosixgaming-arch]

What

Every batch job appends through Append, which reported a null input or output buffer list with a nonzero count as unimplemented. The list the count promises does not exist, so that is a caller error rather than missing behaviour: it now throws std::invalid_argument without writing to the batch, like the library's other invalid arguments. Since Append no longer reaches NotImplemented_nid_no_patch, the seven exports that only build jobs through it (sceAjmBatchJobInitialize, ClearContext, SetGaplessDecode, RunSplit, GetResampleInfo, SetResampleParameters, GetStatistics) count as implemented (libSceAjm.native 21 to 28 of 35).

The existing test expected std::runtime_error; it now expects std::invalid_argument for a null input list and a null output list, and checks that a null list with a zero count is still accepted. No changed line overlaps #4934, #5075, #5307 or #5517.

Tested

Linux (Ubuntu 24.04, GCC 13.3, Release): built the library and its test target, ctest -R guest_ajm passes, tools/check_conventions.py --base origin/main passes. No title tested.

Checklist

• Based on current main; no other open PR implements the same functions
• One topic per PR; follow-ups go in a new PR
• No comments in code except technical debt
• Unimplemented paths throw (NotImplemented_nid_no_patch); silent stubs are listed under Silent stubs in their library's technical debt file
• No notes, investigation .md files or images added to the repository (attach them to this PR)
• New third-party code is a submodule built from source
• Generic behaviour, not specific to one title
• Depends on: none
• Unblocks: none
• GPUs tested: n/a
• AI-assisted: yes

🤖 Generated with Claude Code

https://claude.ai/code/session_01Dh1MhYBFyzxRceoAxrepZ6

[github-actions]

Progress report (91e5f60 → 2e5b4f4)

📈 System libraries: 88.38% (+0.19%, +7 implemented functions)

✅ 7 implemented

Library	Name
libSceAjm.native	sceAjmBatchJobClearContext
libSceAjm.native	sceAjmBatchJobGetResampleInfo
libSceAjm.native	sceAjmBatchJobGetStatistics
libSceAjm.native	sceAjmBatchJobInitialize
libSceAjm.native	sceAjmBatchJobRunSplit
libSceAjm.native	sceAjmBatchJobSetGaplessDecode
libSceAjm.native	sceAjmBatchJobSetResampleParameters

[oneandonlydean]

Closing: no title is known to reach this. With the queue at 700+ open PRs, please hold off on new PRs that don't name a title needing the change until it's down. If a title stops on this on current main, reopen with the title ID and the log line.