Merge R6 Plan 1: cross-port float/double fidelity (field.float → REAL)

field.float now emits SQL REAL (float4, single precision), distinct from
field.double → DOUBLE PRECISION (float8), across all five ports (TS/C#/Java/
Python/Kotlin), with a REAL/DOUBLE plain-decimal wire-normalization rule.

Verified end-to-end: the new Measurement persistence-conformance entity round-trips
REAL/DOUBLE byte-identically across all five ports against Testcontainers Postgres,
with DDL-level "tempC" REAL / "massKg" DOUBLE PRECISION type assertions gating the
REAL-vs-DOUBLE distinction (the dyadic round-trip values alone cannot).

R6 Plan 2 (uuid + @dbColumnType + timestamptz + jsonb) remains.

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

Author: dmealing

docs/superpowers/specs/2026-05-29-conformance-hardening-review.md

@@ -69,7 +69,7 @@ Siblings of the CLI gap — a port can silently lack or diverge on these and sta
 | R3 | **Refresh `spec/conformance-tests.md`** — 5 ports, 7 corpora, fix Java-verify + Drizzle/jOOQ staleness, reclassify codegen as "semantic parity, byte-equivalence excluded" | 4 | doc edit | low — do early; it's the governing contract |
 | R4 | ✅ **DONE (2026-05-29, `cc69ced0`).** `integration-tests.yml` now runs the persistence + api-contract matrix (all 5 ports) on every `pull_request` to `main`, not just release tags / opt-in label — so drift can't merge to main green. | 1 | CI wiring | done |
 | R5 | ✅ **DONE (2026-05-29, ADR-0014).** Fixed at the core: Java `addChild` now validates against the owning loader's registry (not the global singleton); runner composes a per-fixture registry. Multi-tenant correctness fix, not just a test cleanup. | 1 | core change + runner refactor | done |
-| R6 | **Define the float/double normalization rule**, then add float + uuid persistence + loader fixtures | 3 | `normalization.md` rule + fixtures + a uuid in the canonical entity | med — R6a (rule) blocks R6b (fixtures) |
+| R6 | ✅ **Plan 1 (float/double fidelity) DONE (2026-05-29).** `normalization.md` REAL/DOUBLE plain-decimal rule + loader fixtures + `field.float`→REAL (float4) distinct from `field.double`→DOUBLE PRECISION in all 5 ports + the `Measurement` persistence entity (cross-port round-trip **and** DDL `REAL`/`DOUBLE PRECISION` type assertions). Commits `4e4a7253` (Java), `163ef5a6` (Kotlin), `fdafa1eb` (Measurement), + earlier TS/C#/Python on the branch. **Plan 2 (uuid fixtures + `@dbColumnType` + timestamptz + jsonb) still pending.** | 3 | `normalization.md` rule + fixtures + uuid | float done; **uuid/`@dbColumnType` → Plan 2** |
 | R7 | **Kotlin render runner** (or drop Kotlin from the byte-identical claim in CLAUDE.md) | 1/2 | new Kotlin render-conformance test, or doc edit | low-med |
 | R8 | **Register `WARN_*` codes** in `ERROR-CODES.json`; migrate the 3 legacy string-list warnings to FR5c envelope shape | 3 | fixtures + ERROR-CODES.json | low |
 | R9 | **Add missing negative fixtures** for the live ERR codes (finding #14), starting with `ERR_SUBTYPE_RULE_VIOLATION` | 3 | fixtures | med |

fixtures/conformance/field-decimal-precision/expected.json

@@ -0,0 +1,33 @@
+{
+  "metadata.root": {
+    "package": "acme",
+    "children": [
+      {
+        "object.entity": {
+          "name": "Reading",
+          "children": [
+            {
+              "field.long": {
+                "name": "id"
+              }
+            },
+            {
+              "field.decimal": {
+                "name": "amount",
+                "@precision": 12,
+                "@scale": 2
+              }
+            },
+            {
+              "identity.primary": {
+                "@fields": [
+                  "id"
+                ]
+              }
+            }
+          ]
+        }
+      }
+    ]
+  }
+}

fixtures/conformance/field-decimal-precision/input/meta.measure.json

@@ -0,0 +1,17 @@
+{
+  "metadata.root": {
+    "package": "acme",
+    "children": [
+      {
+        "object.entity": {
+          "name": "Reading",
+          "children": [
+            { "field.long": { "name": "id" } },
+            { "field.decimal": { "name": "amount", "@precision": 12, "@scale": 2 } },
+            { "identity.primary": { "@fields": "id" } }
+          ]
+        }
+      }
+    ]
+  }
+}

fixtures/conformance/field-double-array/expected.json

@@ -0,0 +1,32 @@
+{
+  "metadata.root": {
+    "package": "acme",
+    "children": [
+      {
+        "object.entity": {
+          "name": "Reading",
+          "children": [
+            {
+              "field.long": {
+                "name": "id"
+              }
+            },
+            {
+              "field.double": {
+                "name": "amounts",
+                "isArray": true
+              }
+            },
+            {
+              "identity.primary": {
+                "@fields": [
+                  "id"
+                ]
+              }
+            }
+          ]
+        }
+      }
+    ]
+  }
+}

fixtures/conformance/field-double-array/input/meta.measure.json

@@ -0,0 +1,17 @@
+{
+  "metadata.root": {
+    "package": "acme",
+    "children": [
+      {
+        "object.entity": {
+          "name": "Reading",
+          "children": [
+            { "field.long": { "name": "id" } },
+            { "field.double": { "name": "amounts", "isArray": true } },
+            { "identity.primary": { "@fields": "id" } }
+          ]
+        }
+      }
+    ]
+  }
+}

fixtures/conformance/field-double-basic/expected.json

@@ -0,0 +1,31 @@
+{
+  "metadata.root": {
+    "package": "acme",
+    "children": [
+      {
+        "object.entity": {
+          "name": "Reading",
+          "children": [
+            {
+              "field.long": {
+                "name": "id"
+              }
+            },
+            {
+              "field.double": {
+                "name": "amount"
+              }
+            },
+            {
+              "identity.primary": {
+                "@fields": [
+                  "id"
+                ]
+              }
+            }
+          ]
+        }
+      }
+    ]
+  }
+}

fixtures/conformance/field-double-basic/input/meta.measure.json

@@ -0,0 +1,17 @@
+{
+  "metadata.root": {
+    "package": "acme",
+    "children": [
+      {
+        "object.entity": {
+          "name": "Reading",
+          "children": [
+            { "field.long": { "name": "id" } },
+            { "field.double": { "name": "amount" } },
+            { "identity.primary": { "@fields": "id" } }
+          ]
+        }
+      }
+    ]
+  }
+}

fixtures/conformance/field-float-basic/expected.json

@@ -0,0 +1,31 @@
+{
+  "metadata.root": {
+    "package": "acme",
+    "children": [
+      {
+        "object.entity": {
+          "name": "Reading",
+          "children": [
+            {
+              "field.long": {
+                "name": "id"
+              }
+            },
+            {
+              "field.float": {
+                "name": "amount"
+              }
+            },
+            {
+              "identity.primary": {
+                "@fields": [
+                  "id"
+                ]
+              }
+            }
+          ]
+        }
+      }
+    ]
+  }
+}

fixtures/conformance/field-float-basic/input/meta.measure.json

@@ -0,0 +1,17 @@
+{
+  "metadata.root": {
+    "package": "acme",
+    "children": [
+      {
+        "object.entity": {
+          "name": "Reading",
+          "children": [
+            { "field.long": { "name": "id" } },
+            { "field.float": { "name": "amount" } },
+            { "identity.primary": { "@fields": "id" } }
+          ]
+        }
+      }
+    ]
+  }
+}

fixtures/persistence-conformance/canonical/meta.fitness.json

@@ -27,6 +27,16 @@
           { "identity.reference": { "name": "fkProgram", "@fields": "programId", "@references": "Program" } }
         ]
       }},
+      { "object.entity": {
+        "name": "Measurement",
+        "children": [
+          { "source.rdb": { "@table": "measurements" } },
+          { "field.long":   { "name": "id" } },
+          { "field.float":  { "name": "tempC",  "@required": true } },
+          { "field.double": { "name": "massKg", "@required": true } },
+          { "identity.primary": { "@fields": "id", "@generation": "increment" } }
+        ]
+      }},
       { "object.entity": {
         "name": "ProgramView",
         "children": [