The postfix `::` coercion arm folds the letter-led <value>::Type surface
(plan_values_02.md §1b) onto any completed postfix receiver — (a + b)::usize,
f()::T, a.b::T, xs[i]::T — where before only literals (8::i32) and lists
([1,2,3]::List) carried a coercion inline and bare idents (x::u8) rode the path
surface. Parser wraps the receiver in a CoercionExpr; resolve lowers it to a new
hir::ExprKind::Coerce { value }; the checker types the node at the target via the
ONE §1.4 coercion law (coerce_scalar_into, now shared with the local-path
surface); the Floor pass rides the ONE coerce entry (a scalar ireduce/sextend, an
identity retype a no-op). No new floor leaf, no per-receiver arm, no by-name probe
— the value-vs-access split (§1b) needs no parser decision, since a wrapped
postfix receiver is always a value and a bare path consumes its own :: segments.

- The stale OWNED-DEBT comment (value_turbofish.rs) claiming the letter form is
  unimplemented language-wide is deleted — replaced by an accurate one-liner.
- todo_effect/trap.md ratcheted down 3 lines: the new :: postfix arm removes 3
  match-recovery cascade diagnostics (0 new).

Proof: 5 parser goldens (call/member/index/paren-arith accepted; Suit::Hearts
still a path), 1 types golden (coercion applies clean on postfix receivers), and
the coerce_postfix runtime stone ((a+b)::u8 narrow, (a+b)::usize into a strict
usize param, src()::u8) exit-42, registered.

@@ -442,0 +460,4 @@
+                }
+                fb.ins().return_(&[]);
+            } else {
+                let mut rets = Vec::new();

@@ -0,0 +144,4 @@
+}
+
+impl Teardown {
+    fn new(name: &str) -> Self {

@@ -0,0 +117,4 @@
+        .arg("-d")
+        .arg(binary)
+        .output()
+        .expect("spawn `readelf`");