feat(lua_engine): tag FUTURE items with GitHub issues

- Add GitHub issue references to FUTURE comments in LuaEngine
- FUTURE(#299): Execute actual precompiled bytecode instead of re-parsing source
- FUTURE(#300): Capture actual logs from Lua print statements
- FUTURE(#301): Implement memory tracking with platform-specific APIs
- Include comprehensive design document for Issue #254

All LuaEngine tests passing (18/18)
Design document: docs/design/issue-254-lua-engine-implementation.md

closes #254

Author: milliondreams

crates/mandrel-mcp-th/Cargo.toml

@@ -53,7 +53,7 @@ uuid = { version = "1.0", features = ["v4", "serde"] }
 chrono = { version = "0.4", features = ["serde"] }
 
 # Script execution engines
-mlua = { version = "0.9", features = ["lua54", "async", "vendored"] }
+mlua = { version = "0.9", features = ["lua54", "async", "vendored", "serialize"] }
 rquickjs = { version = "0.9", features = ["array-buffer", "futures"] }
 pyo3 = { version = "0.21", features = ["auto-initialize"] }