audit-ct-tidy: close milestone ct-tidy via ctt.tidy

docs/roadmap.md

@@ -88,14 +88,14 @@ context. Pick the next milestone from P1.)_
   the JSON path carries is missing. Plausibly applies to every CLI
   subcommand that calls `load_workspace(&path)?` directly.
   - context: JOURNAL 2026-05-11 ("Iteration ct.1") — surfaced by ct.1.8 tester.
-- [ ] **\[todo\]** Retire dead `KindMismatch` arm — `validate_classdefs`'s
+- [x] **\[todo\]** Retire dead `KindMismatch` arm — `validate_classdefs`'s
   `walk_kind_mismatch` path is structurally unreachable through
   well-formed schema post-ct.1 (the canonical-form validator catches
   the malformed `Type::Con { name: param }` shape earlier). The
   enum variant + `walk_kind_mismatch` helper stay as dead-but-defensive
   code; a future tidy can delete both.
-  - context: JOURNAL 2026-05-11 ("Iteration ct.1").
-- [ ] **\[todo\]** Re-key `Registry.type_def_module` to handle
+  - context: JOURNAL 2026-05-11 ("Iteration ct.1"); closed by iter ctt.3 — variant + helper + dispatch + Display arm all deleted; canonical-form-rejection test stays green asserting `BareCrossModuleTypeRef`.
+- [x] **\[todo\]** Re-key `Registry.type_def_module` to handle
   bare-name-collision-across-modules — `BTreeMap<String, String>` keyed
   by bare type name silently overwrites when two modules each define
   `type Foo`; `normalize_type_for_registry` would then collapse `M.Foo`