feat(conformance): SP-H Unit10 — add field.date/field.time metamodel fixtures + resolve Kotlin metamodel-corpus coverage

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: dmealing

docs/superpowers/plans/2026-06-03-sp-h-field-subtype-hardening-plan.md

@@ -52,7 +52,7 @@ For EACH port (one unit): implement `op: roundtrip` in the port's persistence ru
 - [ ] Review + simplify gate. Commit `feat(metadata): SP-H Unit9 — cross-port filter-op reconciliation (uuid/currency) + filterable-without-ops guard + fixture`.
 
 ### Unit 10: Coverage holes (metamodel + Kotlin corpus + boolean/object/date/time)
-- [ ] Add `field.date`/`field.time` to the metamodel `fixtures/conformance/` corpus; add `field.boolean` + a typed `field.object` to the persistence WRITE round-trip corpus (Unit 3). **Wire Kotlin to run the shared metamodel `fixtures/conformance/` corpus** (or document why not). All 5 ports green. Review + simplify. Commit `feat(conformance): SP-H Unit10 — close field-subtype coverage holes (date/time metamodel, boolean/object roundtrip, Kotlin metamodel corpus)`.
+- [x] **DONE.** Added the `field-date-time-basic` metamodel fixture (`field.date` + `field.time` on one entity) to `fixtures/conformance/`; all four metamodel runners (TS / C# / Java / Python) discover + pass it (TS 304→306, Java 306, C# 558, Python green). **`field.boolean` + a typed `field.object` are already covered by the Unit 3 `AllTypes` op:roundtrip persistence scenario** (`bVal`, `settings` jsonb) — no new persistence work. **Kotlin metamodel corpus: DOCUMENTED, not wired (the principled answer).** Kotlin has no distinct loader/parser/serializer — `metadata-ktx`'s `Loader.kt` forwards directly to the Java `metadata` module's `MetaDataLoader`, which Java already runs the full corpus against (`ConformanceTest`); a parallel Kotlin run would re-invoke identical bytecode for zero added coverage. Kotlin's distinct surfaces (codegen/runtime) are gated by render/persistence/api-contract corpora, and its emitted vocabulary is byte-gated by `registry-conformance`. Documented in `fixtures/conformance/README.md`. Commit `feat(conformance): SP-H Unit10 — add field.date/field.time metamodel fixtures + resolve Kotlin metamodel-corpus coverage`.
 
 ## Phase 4 — Matrix gate + finish
 

fixtures/conformance/README.md

@@ -12,9 +12,23 @@ an `@`-prefixed attribute in alphabetical order. `expected.json` and
 `expected-effective.json` are the authoritative reference for the shape — when
 in doubt, read one.
 
-Port status: TypeScript reference (v0.3) passes the full corpus; C# loader +
-conformance shipped; Java H3a (loader restructure) shipped 2026-05-19, H3b
-(conformance harness) in progress; Python planned.
+Port status: the **metamodel loader + canonical serializer corpus is run by
+four ports — TypeScript, C#, Java, and Python — all green.**
+
+**Kotlin runs this corpus transitively, not as a separate run — by design.**
+Kotlin has no distinct loader, parser, or canonical-serializer surface: the
+`metadata-ktx` facade (`com.metaobjects.metadata.ktx.Loader`) forwards every
+call straight to `MetaDataLoader` in the Java `metadata` module, which is the
+single JVM implementation of the load/parse/canonical-serialize path this corpus
+exercises. Java already runs the full corpus against that exact code
+(`metadata/src/test/java/com/metaobjects/conformance/ConformanceTest.java`), so
+wiring a parallel Kotlin metamodel-corpus run would re-invoke identical bytecode
+through a Kotlin harness — redundant, with zero added coverage. Kotlin's
+*distinct* surfaces (codegen via `codegen-kotlin`, runtime via Exposed) are gated
+by their own corpora (render-conformance, persistence-conformance, and
+api-contract-conformance, all of which Kotlin runs as a first-class port). The
+shared metamodel **vocabulary** Kotlin emits is additionally byte-gated by
+`fixtures/registry-conformance/` (Kotlin is live + green there).
 
 ## A scenario directory
 

fixtures/conformance/field-date-time-basic/expected.json

@@ -0,0 +1,36 @@
+{
+  "metadata.root": {
+    "package": "acme",
+    "children": [
+      {
+        "object.entity": {
+          "name": "Appointment",
+          "children": [
+            {
+              "field.long": {
+                "name": "id"
+              }
+            },
+            {
+              "field.date": {
+                "name": "scheduledOn"
+              }
+            },
+            {
+              "field.time": {
+                "name": "startsAt"
+              }
+            },
+            {
+              "identity.primary": {
+                "@fields": [
+                  "id"
+                ]
+              }
+            }
+          ]
+        }
+      }
+    ]
+  }
+}

fixtures/conformance/field-date-time-basic/input/meta.schedule.json

@@ -0,0 +1,36 @@
+{
+  "metadata.root": {
+    "package": "acme",
+    "children": [
+      {
+        "object.entity": {
+          "name": "Appointment",
+          "children": [
+            {
+              "field.long": {
+                "name": "id"
+              }
+            },
+            {
+              "field.date": {
+                "name": "scheduledOn"
+              }
+            },
+            {
+              "field.time": {
+                "name": "startsAt"
+              }
+            },
+            {
+              "identity.primary": {
+                "@fields": [
+                  "id"
+                ]
+              }
+            }
+          ]
+        }
+      }
+    ]
+  }
+}