fieldtest close: canonical-type-names — route findings + roadmap update

Per-iter journal entry for the fieldtest run plus INDEX pointer.
Roadmap absorbs four actionable findings as P2/P3 todos (split the
merged BadCrossModuleTypeRef diagnostic, workspace subdir search,
`ail check` on `.ailx` extension, `.ailx` counterpart for the
canonical happy-path JSON exhibit). The two carry-on items
(`(import prelude)` doc-gap, the working ones) stay as notes in the
fieldtest spec only. P0 Floats milestone removed — closed
2026-05-10 and no longer load-bearing context.

No bug findings, so no debug dispatch. canonical-type-names is fully
shipped.

docs/roadmap.md

@@ -35,20 +35,9 @@ work progresses.
 
 ## P0 — In flight
 
-- [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
-  is real and surfaces through `Maybe`-shaped comparators rather
-  than through a lying total instance). `Ord` likewise partial:
-  `compare : Float → Float → Maybe Ordering`. Includes literal
-  syntax in Form-A + Surface, codegen for arithmetic ops,
-  conversions Int↔Float, and `Show`-style printing without the
-  typeclass machinery (the typeclass wiring lands in Post-22
-  Prelude).
-  - context: this conversation (2026-05-10) — Float status quo
-    was "documented as a primitive but never implemented";
-    `crates/ailang-core/src/canonical.rs:14` says "no floats".
+_(empty — canonical-type-names milestone closed 2026-05-11; Floats
+closed 2026-05-10 and was removed once it stopped being load-bearing
+context. Pick the next milestone from P1.)_
 
 ## P1 — Next
 
@@ -156,6 +145,34 @@ work progresses.
   block, or extract JSON-schema blocks into a machine-readable
   file the test consumes.
   - context: JOURNAL 2026-05-10 ("Audit close").
+- [ ] **\[todo\]** Split `BadCrossModuleTypeRef` into two diagnostics —
+  the current single shape collapses unknown-owner and
+  known-owner / unknown-type-in-owner into one message. The two
+  cases suggest different fixes (add `(import <owner>)` vs. fix the
+  type name). In the known-owner branch, list the owner's available
+  type defs as candidates the way `bare-cross-module-type-ref`
+  lists candidates from imports.
+  - context: fieldtest 2026-05-11 — `examples/ct_3*.ailx` exhibits both branches with identical-shape diagnostics.
+- [ ] **\[todo\]** Workspace search beyond entry-module's directory —
+  `load_workspace` only finds sibling `.ail.json` files in the same
+  directory as the entry module, so any consumer of prelude/std in a
+  subdirectory has no way to resolve cross-module imports. Add either
+  a `--workspace-root` flag on `ail check` / `ail build` / `ail run`,
+  or upward-search from the entry module's directory. Alternatively
+  ratify the flat-workspace assumption in DESIGN.md if intentional.
+  - context: fieldtest 2026-05-11 — fieldtest fixtures could not be
+    placed under `examples/fieldtest/` because of this; predates the
+    canonical-type-names milestone but surfaces every time.
+- [ ] **\[todo\]** `ail check`/`build`/`run` accept `.ailx` extension —
+  today `ail check foo.ailx` produces a misleading JSON-parse error
+  (`json: expected value at line 1 column 1`) because the loader only
+  accepts `.ail.json`. Either teach the CLI subcommands to auto-parse
+  `.ailx` internally, or detect the extension and emit a
+  "did you mean `ail parse foo.ailx`?" hint. The LLM-author's natural
+  first command should not be the one that produces a misleading
+  diagnostic.
+  - context: fieldtest 2026-05-11 — orthogonal to canonical-type-names
+    but every fieldtest invocation hits this on its first command.
 - [ ] **\[todo\]** `check_in_workspace` per-module overlay narrowing —
   `crates/ailang-check/src/lib.rs:1234` still clears+rebuilds
   `env.ctor_index` per-module; ct.3.2 narrowed the analogous mono
@@ -169,6 +186,15 @@ work progresses.
 
 ## P3 — Ideas
 
+- [ ] **\[todo\]** `compare_primitives_smoke.ailx` counterpart —
+  the canonical happy-path exhibit for canonical-type-names ships
+  only as JSON. Per Decision 6, Surface is the LLM-author surface;
+  the milestone should have a `.ailx` counterpart. Two paths: author
+  `examples/compare_primitives_smoke.ailx` to round-trip into the
+  existing JSON, OR retire the JSON fixture in favour of
+  `examples/ct_1_ordering_signum.{ailx,ail.json}` as the new canonical
+  happy-path exhibit.
+  - context: fieldtest 2026-05-11 (spec_gap).
 - [ ] **\[todo\]** Codegen `lookup_ctor_in_pattern` type-anchoring —
   `crates/ailang-codegen/src/lib.rs:1790` still walks every module's
   ctor_index by bare ctor name. Plumbing the scrutinee's