044 runtime run budget

// Test: std/runtime:run enforces budget via scope cost

~import std/runtime
~import std/io

~pub event expensive {}

~proc expensive|zig {
}

~std/runtime:register(scope: "budget") {
    expensive(10)
}

const TEST_SOURCE = "~expensive()";

~std/runtime:run(source: TEST_SOURCE, scope: "budget", budget: 5)
| result _ |> std/io:print.ln("OK")
| exhausted _ |> std/io:print.ln("EXHAUSTED")
| parse-error _ |> std/io:print.ln("PARSE ERROR")
| validation-error _ |> std/io:print.ln("VALIDATION ERROR")
| shape-error _ |> std/io:print.ln("SHAPE ERROR")
| event-denied _ |> std/io:print.ln("EVENT DENIED")
| dispatch-error _ |> std/io:print.ln("DISPATCH ERROR")
| scope-not-found _ |> std/io:print.ln("SCOPE NOT FOUND")