Implement Warden module execution foundation (Phase 1 & 2)

Added architecture for loading and executing native x86 Warden modules:

New classes:
- WardenModule: Individual module loader with 8-step pipeline
  ✅ MD5 verification (working)
  ✅ RC4 decryption (working)
  ⏳ RSA/zlib/exe-parsing/relocation/API-binding/execution (TODOs)
- WardenModuleManager: Module lifecycle and disk caching
  ~/.local/share/wowee/warden_cache/<MD5>.wdn
- WardenFuncList: Callback structure for module execution

Integration:
- Added wardenModuleManager_ to GameHandler
- Module manager initialized on startup
- Foundation ready for phases 3-7 (validation → execution)

Documentation:
- WARDEN_MODULE_ARCHITECTURE.md (comprehensive 7-phase roadmap)
- Estimated 2-3 months for full native code execution
- Alternative: packet capture approach (1-2 weeks)

Status: Crypto layer complete, execution layer TODO

include/game/game_handler.hpp

@@ -22,6 +22,7 @@
 namespace wowee::game {
     class TransportManager;
     class WardenCrypto;
+    class WardenModuleManager;
 }
 
 namespace wowee {
@@ -1188,6 +1189,7 @@ private:
     uint32_t wardenPacketsAfterGate_ = 0;
     bool wardenCharEnumBlockedLogged_ = false;
     std::unique_ptr<WardenCrypto> wardenCrypto_;
+    std::unique_ptr<WardenModuleManager> wardenModuleManager_;
 
     // ---- XP tracking ----
     uint32_t playerXp_ = 0;