feat: add Lua 5.1 addon system with .toc loader and /run command

Foundation for WoW-compatible addon support:

- Vendor Lua 5.1.5 source as a static library (extern/lua-5.1.5)
- TocParser: parses .toc files (## directives + file lists)
- LuaEngine: Lua 5.1 VM with sandboxed stdlib (no io/os/debug),
  WoW-compatible print() that outputs to chat, GetTime() stub
- AddonManager: scans Data/interface/AddOns/ for .toc files,
  loads .lua files on world entry, skips LoadOnDemand addons
- /run <code> slash command for inline Lua execution
- HelloWorld test addon that prints to chat on load

Integration: AddonManager initialized after asset manager, addons
loaded once on first world entry, reset on logout. XML frame
parsing is deferred to a future step.

extern/lua-5.1.5/src/lopcodes.c

@@ -0,0 +1,102 @@
+/*
+** $Id: lopcodes.c,v 1.37.1.1 2007/12/27 13:02:25 roberto Exp $
+** See Copyright Notice in lua.h
+*/
+
+
+#define lopcodes_c
+#define LUA_CORE
+
+
+#include "lopcodes.h"
+
+
+/* ORDER OP */
+
+const char *const luaP_opnames[NUM_OPCODES+1] = {
+  "MOVE",
+  "LOADK",
+  "LOADBOOL",
+  "LOADNIL",
+  "GETUPVAL",
+  "GETGLOBAL",
+  "GETTABLE",
+  "SETGLOBAL",
+  "SETUPVAL",
+  "SETTABLE",
+  "NEWTABLE",
+  "SELF",
+  "ADD",
+  "SUB",
+  "MUL",
+  "DIV",
+  "MOD",
+  "POW",
+  "UNM",
+  "NOT",
+  "LEN",
+  "CONCAT",
+  "JMP",
+  "EQ",
+  "LT",
+  "LE",
+  "TEST",
+  "TESTSET",
+  "CALL",
+  "TAILCALL",
+  "RETURN",
+  "FORLOOP",
+  "FORPREP",
+  "TFORLOOP",
+  "SETLIST",
+  "CLOSE",
+  "CLOSURE",
+  "VARARG",
+  NULL
+};
+
+
+#define opmode(t,a,b,c,m) (((t)<<7) | ((a)<<6) | ((b)<<4) | ((c)<<2) | (m))
+
+const lu_byte luaP_opmodes[NUM_OPCODES] = {
+/*       T  A    B       C     mode		   opcode	*/
+  opmode(0, 1, OpArgR, OpArgN, iABC) 		/* OP_MOVE */
+ ,opmode(0, 1, OpArgK, OpArgN, iABx)		/* OP_LOADK */
+ ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_LOADBOOL */
+ ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_LOADNIL */
+ ,opmode(0, 1, OpArgU, OpArgN, iABC)		/* OP_GETUPVAL */
+ ,opmode(0, 1, OpArgK, OpArgN, iABx)		/* OP_GETGLOBAL */
+ ,opmode(0, 1, OpArgR, OpArgK, iABC)		/* OP_GETTABLE */
+ ,opmode(0, 0, OpArgK, OpArgN, iABx)		/* OP_SETGLOBAL */
+ ,opmode(0, 0, OpArgU, OpArgN, iABC)		/* OP_SETUPVAL */
+ ,opmode(0, 0, OpArgK, OpArgK, iABC)		/* OP_SETTABLE */
+ ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_NEWTABLE */
+ ,opmode(0, 1, OpArgR, OpArgK, iABC)		/* OP_SELF */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_ADD */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_SUB */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_MUL */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_DIV */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_MOD */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_POW */
+ ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_UNM */
+ ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_NOT */
+ ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_LEN */
+ ,opmode(0, 1, OpArgR, OpArgR, iABC)		/* OP_CONCAT */
+ ,opmode(0, 0, OpArgR, OpArgN, iAsBx)		/* OP_JMP */
+ ,opmode(1, 0, OpArgK, OpArgK, iABC)		/* OP_EQ */
+ ,opmode(1, 0, OpArgK, OpArgK, iABC)		/* OP_LT */
+ ,opmode(1, 0, OpArgK, OpArgK, iABC)		/* OP_LE */
+ ,opmode(1, 1, OpArgR, OpArgU, iABC)		/* OP_TEST */
+ ,opmode(1, 1, OpArgR, OpArgU, iABC)		/* OP_TESTSET */
+ ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_CALL */
+ ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_TAILCALL */
+ ,opmode(0, 0, OpArgU, OpArgN, iABC)		/* OP_RETURN */
+ ,opmode(0, 1, OpArgR, OpArgN, iAsBx)		/* OP_FORLOOP */
+ ,opmode(0, 1, OpArgR, OpArgN, iAsBx)		/* OP_FORPREP */
+ ,opmode(1, 0, OpArgN, OpArgU, iABC)		/* OP_TFORLOOP */
+ ,opmode(0, 0, OpArgU, OpArgU, iABC)		/* OP_SETLIST */
+ ,opmode(0, 0, OpArgN, OpArgN, iABC)		/* OP_CLOSE */
+ ,opmode(0, 1, OpArgU, OpArgN, iABx)		/* OP_CLOSURE */
+ ,opmode(0, 1, OpArgU, OpArgN, iABC)		/* OP_VARARG */
+};
+