Function budget_from_env 

pub fn budget_from_env(var: &str, default: usize) -> usize

Read a token-budget override from env var var (e.g. WINX_CODING_TOKEN_BUDGET), falling back to default when unset, zero, or unparseable. Lets large-context clients tune how much of each file is pulled into context — and how much saved memory is kept — without a rebuild.