feat(LuaGame): Lua interpreter game engine with audio, 17 FPS, 4.5x ball speed

- Embed Lua 5.4.7 source to avoid missing symbols (clearerr, clock, getenv, etc)
- Provide local stubs for missing libc and avoid unexported LVGL cache APIs
- Fix float handling in sys.* bindings (checknumber vs checkinteger)
- Move Lua init and game loop to dedicated 16K FreeRTOS task to avoid GUI 4K stack overflow
- Implement sys API: clear, print (8x8 bitmap font direct FB), rect, circle, line, touch, sfx, tone
- Audio via SfxEngine (SfxId mapping, playNote for tone)
- Ball speed 2 -> 4.5, FPS counter (~17 FPS after direct FB text optimization)
- Supports loading from /sdcard/lua/breakout.lua and embedded fallback
- Verified symbols: 0 missing, builds esp32s3, installs on 192.168.68.107

Apps/LuaGame/main/Source/lua/lstring.h

@@ -0,0 +1,57 @@
+/*
+** $Id: lstring.h $
+** String table (keep all strings handled by Lua)
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lstring_h
+#define lstring_h
+
+#include "lgc.h"
+#include "lobject.h"
+#include "lstate.h"
+
+
+/*
+** Memory-allocation error message must be preallocated (it cannot
+** be created after memory is exhausted)
+*/
+#define MEMERRMSG       "not enough memory"
+
+
+/*
+** Size of a TString: Size of the header plus space for the string
+** itself (including final '\0').
+*/
+#define sizelstring(l)  (offsetof(TString, contents) + ((l) + 1) * sizeof(char))
+
+#define luaS_newliteral(L, s)	(luaS_newlstr(L, "" s, \
+                                 (sizeof(s)/sizeof(char))-1))
+
+
+/*
+** test whether a string is a reserved word
+*/
+#define isreserved(s)	((s)->tt == LUA_VSHRSTR && (s)->extra > 0)
+
+
+/*
+** equality for short strings, which are always internalized
+*/
+#define eqshrstr(a,b)	check_exp((a)->tt == LUA_VSHRSTR, (a) == (b))
+
+
+LUAI_FUNC unsigned int luaS_hash (const char *str, size_t l, unsigned int seed);
+LUAI_FUNC unsigned int luaS_hashlongstr (TString *ts);
+LUAI_FUNC int luaS_eqlngstr (TString *a, TString *b);
+LUAI_FUNC void luaS_resize (lua_State *L, int newsize);
+LUAI_FUNC void luaS_clearcache (global_State *g);
+LUAI_FUNC void luaS_init (lua_State *L);
+LUAI_FUNC void luaS_remove (lua_State *L, TString *ts);
+LUAI_FUNC Udata *luaS_newudata (lua_State *L, size_t s, int nuvalue);
+LUAI_FUNC TString *luaS_newlstr (lua_State *L, const char *str, size_t l);
+LUAI_FUNC TString *luaS_new (lua_State *L, const char *str);
+LUAI_FUNC TString *luaS_createlngstrobj (lua_State *L, size_t l);
+
+
+#endif