Ports battle-tested stdlib extensions from an internal Lua runtime
into `a`, giving scripts a rich set of built-ins with no setup:
- math: round, clamp, isFinite, sign, scale
- table: filter/map/reduce variants, merge/deepMerge/deepCopy,
min/max/mean/sum, keys/values, contains/find, isEmpty,
reverse, readonly
- utils: NULL sentinel, toJSON/fromJSON, dump, try/tryn
- os: microtime() (sub-second timestamp), async sleep()
- log: trace/debug/info/warn/error (routed to RUST_LOG)
Lua stdlib files are embedded via include_str! for a single-binary
distribution. os.sleep uses create_async_function so it yields
to tokio instead of blocking the thread.
