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/auth/auth_packets.hpp

@@ -130,7 +130,8 @@ struct RealmListResponse {
 // REALM_LIST response parser
 class RealmListResponseParser {
 public:
-    static bool parse(network::Packet& packet, RealmListResponse& response);
+    // protocolVersion: 3 = vanilla (uint8 realmCount, uint32 icon), 8 = WotLK (uint16 realmCount, uint8 icon)
+    static bool parse(network::Packet& packet, RealmListResponse& response, uint8_t protocolVersion = 8);
 };
 
 } // namespace auth

include/auth/vanilla_crypt.hpp

@@ -0,0 +1,58 @@
+#pragma once
+
+#include <cstdint>
+#include <vector>
+
+namespace wowee {
+namespace auth {
+
+/**
+ * Vanilla/TBC WoW Header Cipher
+ *
+ * Used for encrypting/decrypting World of Warcraft packet headers
+ * in vanilla (1.x) and TBC (2.x) clients. This is a simple XOR+addition
+ * chaining cipher that uses the raw 40-byte SRP session key directly.
+ *
+ * Algorithm (encrypt):
+ *   encrypted = (plaintext ^ key[index]) + previousEncrypted
+ *   index = (index + 1) % keyLen
+ *
+ * Algorithm (decrypt):
+ *   plaintext = (encrypted - previousEncrypted) ^ key[index]
+ *   index = (index + 1) % keyLen
+ */
+class VanillaCrypt {
+public:
+    VanillaCrypt() = default;
+    ~VanillaCrypt() = default;
+
+    /**
+     * Initialize the cipher with the raw session key
+     * @param sessionKey 40-byte session key from SRP auth
+     */
+    void init(const std::vector<uint8_t>& sessionKey);
+
+    /**
+     * Encrypt outgoing header bytes (CMSG: 6 bytes)
+     * @param data Pointer to header data to encrypt in-place
+     * @param length Number of bytes to encrypt
+     */
+    void encrypt(uint8_t* data, size_t length);
+
+    /**
+     * Decrypt incoming header bytes (SMSG: 4 bytes)
+     * @param data Pointer to header data to decrypt in-place
+     * @param length Number of bytes to decrypt
+     */
+    void decrypt(uint8_t* data, size_t length);
+
+private:
+    std::vector<uint8_t> key_;
+    uint8_t sendIndex_ = 0;
+    uint8_t sendPrev_ = 0;
+    uint8_t recvIndex_ = 0;
+    uint8_t recvPrev_ = 0;
+};
+
+} // namespace auth
+} // namespace wowee