add Lua sandbox with timer system (milestones 1-5 complete)

sandbox-test/scripts/test_globals_removed.lua

@@ -0,0 +1,26 @@
+-- Test that dangerous globals are nil
+-- This script should run successfully if sandbox is properly configured
+-- Note: 'require' is intentionally NOT in this list because the sandbox
+-- provides a safe version when app_path is configured
+
+local dangerous = {
+    "os", "io", "debug", "package", "ffi", "jit",
+    "dofile", "loadfile", "load", "loadstring",
+    "rawget", "rawset", "rawequal", "rawlen",
+    "collectgarbage", "newproxy"
+}
+
+local failed = {}
+
+for _, name in ipairs(dangerous) do
+    local value = _G[name]
+    if value ~= nil then
+        table.insert(failed, name .. " (is " .. type(value) .. ")")
+    end
+end
+
+if #failed > 0 then
+    error("FAIL: These globals should be nil: " .. table.concat(failed, ", "))
+end
+
+print("PASS: All dangerous globals removed")