iter gc.1: retire Spec-23, roadmap forward-pointer to re-brainstorm

docs/roadmap.md

@@ -50,6 +50,18 @@ context. Pick the next milestone from P1.)_
     closed 2026-05-10 — partial-Eq/Ord-for-Float story is documented
     in DESIGN.md §"Float semantics", so the Prelude can decide
     what's instanced (Show: yes, Eq/Ord: no for Float).
+  - context: Iter 23.1-23.3 shipped Ordering ADT, Eq / Ord classes,
+    primitive instances on Int / Bool / Str, and runtime helpers
+    (`ail_str_eq` / `compare`). Remaining: polymorphic free fns
+    (`ne` / `lt` / `le` / `gt` / `ge`), `Show` class, `print`
+    rewire. The original Spec-23 draft was retired 2026-05-11
+    because it silently assumed polymorphic free fns are
+    mono-specialised the same way as class methods; that assumption
+    is false today. Re-brainstorm pending — `ailang-grounding-check`
+    (gc.1) will be the gating mechanism on the new draft.
+  - depends on: polymorphic-free-fn mono-specialisation (symmetric
+    to class-method monomorphisation in 22b.3) — not currently
+    ratified by any green test.
 
 ## P2 — Medium-term