Vanilla/Turtle WoW support: M2 loading, bone parsing, textures, auth

- Vanilla M2 bone struct (108 bytes) with 28-byte animation tracks
- Version-aware bone parsing (vanilla vs WotLK format detection)
- Fix CharSections.dbc field layout for vanilla (variation/color at 4-5)
- Remove broken CharSections.csv files (all fields marked as strings)
- Expansion data reload on profile switch (DBC cache clear, layout reload)
- Vanilla packet encryption (VanillaCrypt XOR-based header crypt)
- Extended character preview geoset range (0-99) for vanilla models
- DBC cache clear support in AssetManager

include/core/application.hpp

@@ -57,6 +57,7 @@ public:
     game::ExpansionRegistry* getExpansionRegistry() { return expansionRegistry_.get(); }
     pipeline::DBCLayout* getDBCLayout() { return dbcLayout_.get(); }
     pipeline::HDPackManager* getHDPackManager() { return hdPackManager_.get(); }
+    void reloadExpansionData(); // Reload DBC layouts, opcodes, etc. after expansion change
 
     // Singleton access
     static Application& getInstance() { return *instance; }