feat: Add KoikatsuBlenderPipeline addon with import/export functionality

- Add core addon files (__init__.py, KKPanel.py, preferences.py, common.py)
- Add import pipeline with armature, mesh, and material modification modules
- Add export pipeline with material baking and FBX preparation utilities
- Add material combiner tool for texture atlas generation and optimization
- Add extras utilities for animation, rigging, and asset management
- Add bone orientation data from better_fbx for accurate skeletal structure
- Add comprehensive documentation and wiki with multi-language support (EN, JP, ZH)
- Add animation library retargeting lists for ARP and Rokoko motion capture
- Add Rigify integration scripts for advanced rigging workflows
- Add shader file (KK Shader V8.0.blend) for material rendering
- Add manifest and license files for addon distribution
- Add changelog documenting version history and improvements
- Initialize complete Blender addon project for Koikatsu character import/export

wiki/standard_manual_test_cases.md

@@ -0,0 +1,34 @@
+## Test cases
+
+1. In Koikatsu, export Chika with a single outfit (default exporter settings)
+    * Also export with only "Export All Outfits" enabled
+    * Also export with only "Export Variations" and "Export Hit Meshes" checked
+    * Also export with a pose selected, an emotion pattern selected and only "Freeze Current Pose" and "Freeze Shapekeys" checked
+1. In Blender, import the "Export Variations" and "Export Hit Meshes" model
+    * Check variations + hitboxes were separated
+    * Check eye shapekeys work
+    * Check mouth shapekeys work
+    * Check Gag eye shapekeys work
+1. In another file, import the "Freeze Current Pose" and "Freeze Shapekeys" model
+    * Check armature type was changed to Koikatsu
+    * Check pose and shapekeys were applied to base mesh
+1. In another file, import the 8 outfits export
+    * Check Outfits 0, 1, 2 exist, and have textures + converted colors
+    * Check Hair for Outfits 0, 1, 2 exist and have textures + converted colors
+1. In another file, import the default settings export
+    * Check Outfit 0 exists
+    * Check Hair for Outfit 0 exists
+    * Check hand IK, leg IK, hips bone and center bone work
+    * Check eye controller works
+    * Use the bake material templates button
+    * Use the "Prep for target application" button
+1. In another file, import the default settings export with the "Rigify Armature", "Skip modifying shapekeys", "Use Cycles" options. Check "Fix body seams" and enable the "SFW mode" checkbox
+    * Check Rigify hand IK, leg IK, hips bone and center bone work
+    * Check Rigify eye controller works
+    * Check shapekeys were not modified
+    * Switch to rendered view and check the model appears in the cycles viewport
+    * Go into edit mode and check the seam down the middle of the neck is gone
+    * Check the sfw alphamask was applied to the body material
+    * Check nsfw meshes were deleted
+1. In another file, import the default settings export with the "Separate every object" option selected
+    * Check all outfit objects are separated