Add NIF previewer plugin with Linux-specific fixes

Vendored from github.com/Parapets/mo2-preview_nif and adapted for Linux:

- BSA texture resolution via MO2 virtual tree with case-insensitive
  fallback walk (Linux FS is case-sensitive; NIFs reference textures
  with arbitrary case against files on disk)
- Process-wide cached BSA candidate list, keyed by profile path,
  priority-sorted, filtering disabled mods
- Path backslash normalization before loose-file lookup
- Polygon offset on SLSF1_Decal-flagged shapes to break z-ties with
  coincident base meshes (road decals, moss overlays)
- Opaque framebuffer via glColorMask alpha lock so alpha-blended shapes
  can't bleed the dialog background through the preview area
- QMouseEvent::globalPosition().toPoint() for Qt6 compatibility

Preview dialog behavior (organizercore.cpp):
- Switch previewFile and previewFileWithAlternatives from stack-allocated
  exec() to heap + ApplicationModal + show() + WA_DeleteOnClose.
- Parent passed as nullptr so preview lifetime is decoupled from the
  stack-allocated ModInfoDialog that spawns it. Nested exec() inside
  the enclosing dialog's exec() was softlocking on close.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/libs/preview_nif/plugindefinition.json b/libs/preview_nif/plugindefinition.json
new file mode 100644
index 0000000..d0d25c2
--- /dev/null
+++ b/libs/preview_nif/plugindefinition.json
@@ -0,0 +1,42 @@
+{
+    "Name": "Preview NIF",
+    "Author": "Parapets",
+    "Description": "Supports previewing NIF files",
+    "DocsUrl": "",
+    "GithubUrl": "https://github.com/Exit-9B/modorganizer-preview_nif",
+    "NexusUrl": "https://www.nexusmods.com/skyrimspecialedition/mods/69813",
+    "Versions": [
+        {
+            "Version": "0.2.0b",
+            "Released": "2023-11-27",
+            "MinSupport": "2.5.0",
+            "MaxSupport": "2.5.0",
+            "MinWorking": "2.5.0",
+            "MaxWorking": "",
+            "DownloadUrl": "https://github.com/Exit-9B/modorganizer-preview_nif/releases/download/v0.2.0/preview_nif-0.2.0.7z",
+            "PluginPath": [
+                "preview_nif.dll",
+                "data"
+            ],
+            "LocalePath": [],
+            "DataPath": [],
+            "ReleaseNotes": []
+        },
+        {
+            "Version": "0.1.8.1b",
+            "Released": "2022-06-24",
+            "MinSupport": "2.4.3",
+            "MaxSupport": "2.4.4",
+            "MinWorking": "2.4.3",
+            "MaxWorking": "2.4.5a3",
+            "DownloadUrl": "https://github.com/Exit-9B/modorganizer-preview_nif/releases/download/v0.1.8/preview_nif-0.1.8.1.7z",
+            "PluginPath": [
+                "preview_nif.dll",
+                "data"
+            ],
+            "LocalePath": [],
+            "DataPath": [],
+            "ReleaseNotes": []
+        }
+    ]
+}