floats iter 5.4: roadmap — mark Floats [x] + unblock Post-22 Prelude

docs/roadmap.md

@@ -33,7 +33,7 @@ work progresses.
 
 ## P0 — In flight
 
-- [~] **\[milestone\]** Floats — introduce `Float` as IEEE-754
+- [x] **\[milestone\]** Floats — introduce `Float` as IEEE-754
   binary64 primitive type. One float type only (no `f32`).
   IEEE-conformant equality: `eq : Float → Float → Bool` returns
   `false` for `NaN == NaN`; **no `Eq` instance** (the partiality
@@ -55,10 +55,10 @@ work progresses.
   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")
-  - depends on: Floats (the partial-Eq/Ord story for Float must be
-    settled before the Prelude classes ship, so the Prelude can
-    decide what's instanced and what isn't)
+  - 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).
 
 ## P2 — Medium-term