Move Lua C API wrappers from main.zig's lua struct into src/lua.zig
so both main.zig and markers.zig import from the same source. Remove
duplicate lapi struct from markers.zig.
Add DLL-side permission gating on WorldMarker/ClearWorldMarker: calls
WoW's IsPartyLeader (0x4e9130) and IsRaidOfficer (0x4bb910) C
functions directly. Requires party leader, raid leader, or raid
assist to place or clear markers. SetMarkerDef/ClearMarkerDef remain
ungated (addon validates sender before calling).
MarcelineVQ