[XeresRazor]

Fix or feature

• Fix
• Feature

Feature from outside: not applicable, this is a fix.

What and why

Problem. Valkyria Chronicles 4 stops at the shader split ("found no shaders"). Fixes #1279.
Cause. Its shaders are gzip streams of BNSH files, 6,712 in FENRIR_SHADER_NEW_NX64_.HSG and 158 in main. No reader decompresses them.
Change. 0046 adds a reader for them. The split then finds all 6,870, the same set the game creates at boot.

Details

• Every stream has the same ten header bytes (1f 8b 08 00 00 00 00 00 00 0b). The reader takes a stream only with that header, complete and with BNSH inside, and bounds the decoded size. scan_blob calls it for an HSPK file, main() for each version's main.
• Each BNSH holds one stage, so the shaders are single-stage programs (3,435 vertex, 3,435 pixel).
• A temporary host change dumped every program the game creates in its first 60 seconds: the same 6,870 keys as the split, none missing or extra. The change is not in this PR.
• 16 other games' main have no stream with that header, so no other game's tables change.
• The patch is pending: the same change goes to seedds/nxnative as its own PR. The game has no registered profile yet.

Checked

• Tests: python3 tools/engine.py check passes (45 patches apply to upstream 0c078130f6db). The reader has 7 tests. 204 of 206 test files in dm/tools/tests, dm/gfx/tests and dm/ios/tests pass (the other two need .NET in my test shell). The generated doc indexes are current.
• Test for a fix: dm/tools/tests/test_gzip_bnsh.py (synthetic packages and images, no game files).
• Visual QA: not applicable.
• Run on a device or Mac: Valkyria Chronicles 4 01005C600AC68000 1.0.0 (base, 8 DLC), MacBook Pro M1 Max, macOS 27.2. A build from this branch with try-local was installed on the connected iPad Pro 13-inch (M5) from the launcher and reached gameplay (reported by the tester, not measured). Also, the Mac build passes all steps (6,870 of 6,870 shaders translate), and a headless run reached the opening scenes and the first map screen at about 30 fps. iOS shaders: 6,870 of 6,870 compile.
• Not checked: an iPhone, frame rate or memory on the iPad, and how far into gameplay it went.

Screenshots

None, no visible change.

Scope

• No engine file (dm/, scripts/, docs/, ref/) is added to the repository: the change is one patch in patches/, and tools/engine.py check passes.
• 0046 says pending until its seedds/nxnative PR is open.
• No launcher view is changed.
• No keys, game files or data extracted from a game in the change or the attachments.