fix(environment): keep invalid recorded dates unknown

Distinguish invalid supported timestamp spellings from unrecognized legacy formats at the recorded-date owner. Probe replay retains ordinal order for invalid dates without changing the existing legacy fallback.

Validated date parsing, state ordering and comparison workflows; the prior implementation reorders the invalid-date regression.

src/application/environment/environmentCompare.test.ts

@@ -841,28 +841,37 @@ const registerProbeCoverageCases = () => {
 };
 
 const registerProbeOrderingAndCaptureCases = () => {
-  it("keeps the recorded order when a record has no start time, as state extraction does", () => {
-    const { startedDateTime: _undated, ...read } = {
-      ...exchange(1, "GET", "http://app.example/api/books/2", 404),
-      response: {
-        status: 404,
-        content: {
-          mimeType: "application/json",
-          text: JSON.stringify(BOOK_NOT_FOUND),
+  it.each([undefined, "2026-02-30T09:00:00Z"])(
+    "keeps replay in recorded order when a start is missing or invalid: %s",
+    (startedDateTime) => {
+      const { startedDateTime: _undated, ...read } = {
+        ...exchange(1, "GET", "http://app.example/api/books/2", 404),
+        response: {
+          status: 404,
+          content: {
+            mimeType: "application/json",
+            text: JSON.stringify(BOOK_NOT_FOUND),
+          },
         },
-      },
-    };
-    const report = run(
-      analysisViewCaptureEvidence(
-        environmentManifestCaptureFixture([
-          exchange(0, "DELETE", "http://app.example/api/books/2", 204),
-          read,
-        ]),
-      ),
-    );
-    if (!report.ok) throw report.error;
-    expect(report.value.summary).toMatchObject({ steps: 2, equal: 2 });
-  });
+      };
+      const report = run(
+        analysisViewCaptureEvidence(
+          environmentManifestCaptureFixture([
+            exchange(0, "DELETE", "http://app.example/api/books/2", 204),
+            {
+              ...read,
+              ...(startedDateTime === undefined ? {} : { startedDateTime }),
+            },
+          ]),
+        ),
+      );
+      if (!report.ok) throw report.error;
+      expect(report.value.summary).toMatchObject({ steps: 2, equal: 2 });
+      expect(
+        report.value.probes[0]?.results.map(({ ordinal }) => ordinal),
+      ).toEqual([0, 1]);
+    },
+  );
 
   it.each([
     ["2026-10-20T09:00:00.0002Z", "2026-10-20T09:00:00.0001Z"],

src/application/environment/environmentCompareProbe.ts

@@ -19,7 +19,7 @@ import type { JsonValue } from "../../domain/jsonValue.js";
 import {
   compareOffsetDateTimeInstants,
   offsetDateTimeInstantFromEpochMilliseconds,
-  readRecordedDateTime,
+  inspectRecordedDateTime,
   type OffsetDateTimeInstant,
 } from "../../domain/offsetDateTime.js";
 import type { WebNetworkCaptureRecord } from "../../domain/webNetworkCapture.js";
@@ -55,8 +55,9 @@ const startedInstant = (
 ): OffsetDateTimeInstant | undefined => {
   const started = startedSchema.safeParse(record.reported);
   if (!started.success) return undefined;
-  const reading = readRecordedDateTime(started.data.startedDateTime);
-  if (reading !== undefined) return reading.instant;
+  const reading = inspectRecordedDateTime(started.data.startedDateTime);
+  if (reading.kind === "valid") return reading.reading.instant;
+  if (reading.kind === "invalid") return undefined;
   // Preserve native-Date admission for legacy spellings, at its original precision.
   const ms = Date.parse(started.data.startedDateTime);
   return Number.isFinite(ms)

src/domain/offsetDateTime.test.ts

@@ -2,11 +2,24 @@ import { describe, expect, it } from "vitest";
 import { z } from "zod";
 
 import {
+  inspectRecordedDateTime,
   offsetDateTimeSchema,
   readRecordedDateTime,
   utcDateTimeSchema,
 } from "./offsetDateTime.js";
 
+it.each([
+  ["2026-02-30T09:00:00Z", "invalid"],
+  ["1900-02-29 09:00:00", "invalid"],
+  ["2026-10-20T24:00:00Z", "invalid"],
+  ["2026-10-20T09:00:00+24:00", "invalid"],
+  ["2026-10-20 09:00:00.0000000001", "valid"],
+  ["Tue, 20 Oct 2026 09:00:00 GMT", "unrecognized"],
+  ["2026-10-20", "unrecognized"],
+])("classifies recorded spelling %s as %s", (text, kind) => {
+  expect(inspectRecordedDateTime(text).kind).toBe(kind);
+});
+
 const ACCEPTED: readonly (readonly [string, string])[] = [
   ["a UTC timestamp", "2026-10-09T04:00:00Z"],
   ["a positive offset", "2026-10-09T04:00:00+02:00"],

src/domain/offsetDateTime.ts

@@ -55,25 +55,27 @@ export const parseOffsetDateTimeInstant = (
   };
 };
 
-/** Parse recorded ISO spelling once, retaining its exact instant and formatting facts. */
-export const readRecordedDateTime = (
+export interface RecordedDateTimeReading {
+  readonly instant: OffsetDateTimeInstant;
+  readonly spelling: {
+    readonly separator: "T" | " ";
+    readonly secondsPresent: boolean;
+    readonly fractionDigits: number;
+    readonly zone: string;
+  };
+}
+
+/** Distinguish invalid supported spellings from formats this reader does not interpret. */
+export const inspectRecordedDateTime = (
   value: string,
 ):
-  | {
-      readonly instant: OffsetDateTimeInstant;
-      readonly spelling: {
-        readonly separator: "T" | " ";
-        readonly secondsPresent: boolean;
-        readonly fractionDigits: number;
-        readonly zone: string;
-      };
-    }
-  | undefined => {
+  | { readonly kind: "valid"; readonly reading: RecordedDateTimeReading }
+  | { readonly kind: "invalid" | "unrecognized" } => {
   const match =
     /^(\d{4}-\d{2}-\d{2})([T ])(\d{2}:\d{2})(?::(\d{2})(?:\.(\d+))?)?(Z|[+-]\d{2}:?\d{2})?$/u.exec(
       value,
     );
-  if (match === null) return undefined;
+  if (match === null) return { kind: "unrecognized" };
   const [, date, separator, time, seconds, fraction = "", zone = ""] = match;
   const offset =
     zone === ""
@@ -84,18 +86,29 @@ export const readRecordedDateTime = (
   const normalized = offsetDateTimeSchema.safeParse(
     `${date}T${time}${seconds === undefined ? "" : `:${seconds}`}${fraction === "" ? "" : `.${fraction}`}${offset}`,
   );
-  if (!normalized.success) return undefined;
+  if (!normalized.success) return { kind: "invalid" };
   return {
-    instant: parseOffsetDateTimeInstant(normalized.data),
-    spelling: {
-      separator: separator as "T" | " ",
-      secondsPresent: seconds !== undefined,
-      fractionDigits: fraction.length,
-      zone,
+    kind: "valid",
+    reading: {
+      instant: parseOffsetDateTimeInstant(normalized.data),
+      spelling: {
+        separator: separator as "T" | " ",
+        secondsPresent: seconds !== undefined,
+        fractionDigits: fraction.length,
+        zone,
+      },
     },
   };
 };
 
+/** Parse recorded ISO spelling once, retaining its exact instant and formatting facts. */
+export const readRecordedDateTime = (
+  value: string,
+): RecordedDateTimeReading | undefined => {
+  const inspected = inspectRecordedDateTime(value);
+  return inspected.kind === "valid" ? inspected.reading : undefined;
+};
+
 /** Convert a Date.now-style integer into the same exact comparison shape. */
 export const offsetDateTimeInstantFromEpochMilliseconds = (
   epochMilliseconds: number,