{
  "version": "2026-09-18.1",
  "authority": "local reconstructed reference only",
  "owner": "Pan Out research maintainer",
  "scope": "signed-out consumer web",
  "truthRules": {
    "observed": "requires route, state, viewport and capture",
    "measured": "requires reproducible production probe",
    "sourceDerived": "requires authored source selector and hash; unseen runtime remains unverified",
    "reconstructed": "local implementation with explicit source boundary",
    "originalAddition": "guide, test fixture or extension absent from observed production evidence"
  },
  "integration": {
    "routing": "relative HTML href and encoded query strings; no server runtime",
    "accounts": "no authentication; signed-out actions explain the boundary",
    "mutations": "Fixture actions stay in memory; only the local theme preference persists under youtube-fixture-theme. No remote side effects.",
    "telemetry": "none; do not collect raw queries, account identity or watch history",
    "untrustedText": "textContent; never evaluate fixture strings",
    "flags": "no production feature flags inferred; local fixture state is explicit",
    "rollback": "restore previous frozen static package and republish the same private site name",
    "themePersistence": {
      "storage": "localStorage",
      "key": "youtube-fixture-theme",
      "values": [
        "light",
        "dark"
      ],
      "lifetime": "per origin until site storage is cleared",
      "reset": "Clear site storage or set Light from the appearance menu. Fresh browser contexts have no stored preference."
    }
  },
  "qualityBudgets": {
    "firstPageTransferBytes": 5000000,
    "pageHorizontalOverflowPixels": 1,
    "contrastNormalText": 4.5,
    "contrastLargeTextAndUi": 3,
    "minimumTargetCssPixels": 24,
    "preferredTouchTargetCssPixels": 40,
    "referenceWidths": [
      390,
      768,
      1440,
      1920
    ],
    "supportedBrowser": "Chromium 152 via Playwright",
    "otherBrowsers": "not independently verified",
    "assistiveTechnology": "native semantics and accessible snapshots; physical screen-reader matrix not yet independently verified"
  },
  "changeProcess": [
    "record source or original-addition rationale",
    "update local contract and specimen",
    "update denominator and state mapping",
    "verify pointer and keyboard outcomes",
    "verify visual responsive and accessibility effects",
    "freeze exhaustive package and dependency manifests",
    "obtain new isolated judge panel",
    "publish only site and verify live"
  ],
  "deprecation": "Never silently change a stable specimen ID or token meaning. Retain alias and migration note for one reference version.",
  "freshness": "Reinspect live routes before production design use; source changes invalidate affected fidelity claims."
}