057 sole implementation is the handler

// Pins: an abstract tor with exactly ONE implementation and no `proc` default
// runs that implementation.
//
// The pairing pass looks for a default and an override separately. After
// canonicalization stamps the enclosing module onto an unqualified impl, both
// searches match the SAME declaration — so a lone implementation was read as a
// default/override pair and renamed to `greet.default`, leaving the tor with no
// handler at all. The emitter then fabricated a zero value for it, so the
// program compiled, exited 0, and printed nothing.
//
// Both spellings of the implementation are pinned: unqualified, and qualified
// with the file's own module.
~import std/io

~[abstract] tor greet { name: string }
| greeted string
| skipped

~greet => greeted name

~[abstract] tor shout { name: string }
| shouted string
| skipped

~input:shout => shouted name

~greet(name: "world")
| greeted g |> std/io:print.ln(g)
| skipped |> std/io:print.ln("greet was skipped")

~shout(name: "WORLD")
| shouted s |> std/io:print.ln(s)
| skipped |> std/io:print.ln("shout was skipped")