051 runtime run budget autodischarge

// Test: std.runtime:run auto-discharges on budget exhaustion

~import "$std/runtime"
~import "$std/io"

const std = @import("std");

~pub event open_handle {}
| opened { handle: []const u8[opened!] }

~proc open_handle {
    std.debug.print("OPEN\n", .{});
    return .{ .opened = .{ .handle = "h1" } };
}

~pub event close_handle { handle: []const u8[!opened] }
| closed {}

~proc close_handle {
    std.debug.print("CLOSE\n", .{});
    return .{ .closed = .{} };
}

~pub event step {}
| done {}

~proc step {
    std.debug.print("STEP\n", .{});
    return .{ .done = .{} };
}

~std.runtime:register(scope: "api") {
    open_handle(1)
    close_handle(1)
    step(1)
}

const TEST_SOURCE = "~open_handle()\n| opened _ |> step()";

~std.runtime:run(source: TEST_SOURCE, scope: "api", budget: 1)
| 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")
| 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")