007 reject dangling slice

// RED PIN (design gap): read's `| slice` payload BORROWS s.data through a
// terminal branch, and nothing links its lifetime to s — freeing s before
// using the slice compiles today and SIGSEGVs at runtime (exit 139).
// The ratified borrow model (2026-06-11) says terminal payloads must OWN
// what they carry or carry an obligation; this test goes green when that
// rule (or a read-scope design) lands and rejects this program.
~import std/string
~import std/io

~std/string:from-page(text: "hello")
| ok s |> std/string:read(s)
    | slice text |> std/string:free(s) |> std/io:print.ln("{{ text:s }}")
| err _ |> _