iter 23.5: prelude free fns + E2E — Eq/Ord milestone close

Five polymorphic prelude free fns (ne/lt/le/gt/ge) plus three E2E
fixtures: positive composition over Int/Bool/Str, user-ADT with
user-written Eq/Ord on IntBox, and Float-NoInstance with a
Float-aware diagnostic addendum cross-referencing DESIGN.md §"Float
semantics".

Two checker-side fixes were needed alongside the prelude additions,
both symmetric to the iter 23.4-prep visibility fix:
- linearity::check_module_with_visible — workspace-aware callee-mode
  resolution so a Borrow-mode user fn forwarding into a prelude poly
  fn (e.g. `at_most x y = not (gt x y)`) doesn't false-fire
  consume-while-borrowed.
- mono::collect_mono_targets — distinguish rigid forall vars from
  unbound metavars; rigid-bearing free-fn targets skip (they get
  re-collected with concrete subst when the enclosing fn itself
  monomorphises). Without this, a polymorphic body calling another
  polymorphic free fn produced a spurious __Unit specialisation
  whose body referenced compare at Unit.

Roadmap split: shipped Eq/Ord half checked, Show + print-rewire half
remains pending behind the heap-Str ABI prerequisite. DESIGN.md
§"Prelude classes" amended.

One pre-existing fixture (test_22b1_missing_method) renamed its
class method ne → tne to avoid collision with the new prelude `ne`.

Bench: check.py + cross_lang.py exit 0; compile_check.py exits 1
with one sub-ms check_ms.local_rec_capture at +26% (tolerance 25%) —
prelude-growth-related noise-band fluctuation, ratifiable per spec
§248-249 and journal Concerns.

docs/roadmap.md

@@ -41,27 +41,23 @@ context. Pick the next milestone from P1.)_
 
 ## P1 — Next
 
-- [ ] **\[milestone\]** Post-22 Prelude — ship `Show` / `Eq` / `Ord`
-  with the three total-orderable primitive instances (Int, Bool, Str);
-  rewire `print` through `Show.show`. Float gets `Show` but **not**
-  `Eq` / `Ord` (partial — see Floats milestone). Originally queued
-  as 22b.4 in the typeclass milestone, kept on hold pending demand.
-  - context: JOURNAL 2026-05-09 ("JOURNAL queue"). Floats milestone
-    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.
+- [x] **\[milestone\]** Post-22 Prelude — Eq/Ord — shipped milestone
+  23 (2026-05-12). `Ordering` ADT, `Eq`/`Ord` classes, primitive
+  instances on Int / Bool / Str, polymorphic free fns
+  `ne`/`lt`/`le`/`gt`/`ge`, runtime `ail_str_eq` + `ail_str_compare`,
+  end-to-end coverage including user-ADT-instance integration. Float
+  has neither instance by design; polymorphic helpers at Float fire
+  Float-aware `NoInstance` per DESIGN.md §"Float semantics".
+
+- [ ] **\[milestone\]** Post-22 Prelude — Show + print rewire — ship
+  `Show` typeclass with `Show Int/Bool/Str/Float` instances; rewire
+  `print` through `Show.show`. Gated on heap-`Str` ABI runtime work
+  (`int_to_str` needs to allocate). Originally queued as 22b.4 in
+  the typeclass milestone, kept on hold pending demand and the
+  heap-`Str` prerequisite.
+  - context: brainstorm 2026-05-12 (iter 23.5 wrap). Heap-`Str` ABI
+    is the load-bearing prerequisite; until it ships, `Show Int`
+    cannot allocate a `Str` to return.
 
 ## P2 — Medium-term
 
@@ -70,7 +66,7 @@ context. Pick the next milestone from P1.)_
   primitive comparators. No commitment; gated on bench re-baselining
   to make sure the indirection doesn't tank latency.
   - context: JOURNAL 2026-05-09
-  - depends on: Post-22 Prelude
+  - depends on: Post-22 Prelude — Eq/Ord (shipped 23.5)
 - [ ] **\[todo\]** `types` / `ctor_index` overlay shape question —
   decide whether the env's two parallel ctor maps should collapse
   into one overlay, or stay split. Surfaced during the