Add DLL-side minimap NPC tracking with blip rendering

Hook ObjectEnumProc, RenderObjectBlips, and EnumVisibleObjects to classify
visible objects by NPC flags / GO type and render custom blip icons.

Includes Lua API (SetObjectTypeBlip), texture caching, WMO indoor/outdoor
filtering, and coordinate projection. Consolidate vendor subcategories
into single entry since vanilla only has one NPC_FLAG_VENDOR. Spell
tracking entries now toggle off when clicked while active.

Fix: queryMapObjIDs was __fastcall (not __thiscall) — pushing 3 stack
args but RET 0x8 only cleaned 2, corrupting ESP and crashing.

src/main.zig

@@ -96,6 +96,9 @@ fn registerLuaFunctions() void {
         registerFunction("SetCursorScale", @intFromPtr(&bigcursor.luaSetCursorScale));
         registerFunction("GetCursorScale", @intFromPtr(&bigcursor.luaGetCursorScale));
     }
+    if (build_opts.minimapicons and minimapicons.isActive()) {
+        registerFunction("SetObjectTypeBlip", @intFromPtr(&minimapicons.luaSetObjectTypeBlip));
+    }
     if (build_opts.worldmarkers and markers.isActive()) {
         // User-facing functions stay global
         registerFunction("WorldMarker", @intFromPtr(&markers.luaWorldMarker));