Every built-in variable a Bar sets: the price series (OHLCV and its
standard derivations) as history-carrying Value::Series, bar_index as a
plain number, then the per-bar namespaces from register_per_bar.
Register all builtin namespaces as objects and global functions
Returns namespace objects to be loaded as variables (e.g., “array”, “str”, “ta”)
and global builtin functions (e.g., “na”)
Each member stores the builtin function pointer as Value::BuiltinFunction