{
  "schemaVersion": 1,
  "studyDate": "2026-11-11",
  "data": "36 deliberately selected fictional identifier strings. 32 positive decimal IDs and 4 leading-zero diagnostic controls. No assigned Meta ad IDs or customer records.",
  "sampleInterpretation": "Mechanism tests, with no sampling claim about real advertising accounts or a population failure rate.",
  "alignment": "All input and output files are aligned by unique record_id. ad_id is never used to align the comparison.",
  "metric": "Exact equality of the exported ad_id character sequence. Numeric equivalence and cell type are recorded separately.",
  "excel": {
    "product": "Microsoft Excel for Mac",
    "version": "16.93",
    "build": "16.93.25011212",
    "os": "macOS 26.5.2 (25F84)",
    "systemLocale": "ru_UA",
    "interfaceLanguage": "Russian",
    "decimalSeparator": ",",
    "exportSeparator": ";",
    "source": "source-tab.txt",
    "sourceEncoding": "UTF-8, ASCII-only content. The wizard showed Cyrillic (Mac OS).",
    "import": "Native Text Import Wizard, Delimited, tab separator, double-quote qualifier, General columns. The conversion prompt was answered Convert or Don't Convert.",
    "automaticConversions": {"removeLeadingZeros":true,"truncateLongNumbersTo15Digits":true,"convertEToScientific":true,"showCsvConversionWarning":true},
    "routes": [
      {"id":"excel-general","prompt":"Convert","format":"General","width":"Original narrow layout shown in worksheet evidence. Exact character width was not recorded.","export":"Native Save As, CSV UTF-8. Observed UTF-8 BOM and semicolon separators."},
      {"id":"excel-format0","prompt":"Convert","format":"0 applied to B2:B37 in the same imported workbook","export":"Native Save to CSV UTF-8. Bytes captured separately."},
      {"id":"excel-no-convert","prompt":"Don't Convert","format":"General","export":"Fresh native import of the same source tokens, then native Save As CSV UTF-8."}
    ],
    "limits": "No measured Text-column import control, AutoFit comparison or Excel Windows/Web run. Recommendations for those paths are documented guidance."
  },
  "sheets": {
    "product": "Google Sheets cloud service",
    "version": "Cloud version not exposed",
    "locale": "ru_RU",
    "timeZone": "America/Los_Angeles",
    "importRoute": "CSV imported with connected import_spreadsheet using native_google_sheets, then exported as text/csv through Drive. UI File > Import equivalence is not claimed.",
    "readback": "userEnteredValue, effectiveValue, formattedValue, userEnteredFormat.numberFormat and effectiveFormat.numberFormat. Account and source document identifiers are excluded from public evidence.",
    "routes": [
      {"id":"sheets-csv","operation":"Connected CSV import and native Drive CSV export"},
      {"id":"sheets-format0","operation":"Duplicate imported sheet, repeatCell NUMBER pattern 0 on B2:B37, native Drive CSV export"},
      {"id":"sheets-strings","operation":"updateCells stringValue from source, TEXT pattern @ on B2:B37, native Drive CSV export"},
      {"id":"sheets-client-numbers","operation":"Node Number(original) supplies numberValue, NUMBER pattern 0, native Drive CSV export. Client precision loss can precede Sheets."},
      {"id":"sheets-paste","operation":"pasteData PASTE_NORMAL with comma delimiter, native Drive CSV export"},
      {"id":"sheets-quoted","operation":"Fresh connected import of fully quoted CSV, native Drive CSV export"}
    ],
    "exportSelection": "Each target tab was moved to index 0 before Drive CSV export.",
    "repeat": "A second fresh import and a quoted CSV import returned byte-identical CSV exports to the first import.",
    "limits": "No direct values.update RAW/USER_ENTERED endpoint experiment and no browser File > Import UI experiment."
  },
  "javascript": {
    "runtime": "Node.js v26.0.0",
    "operation": "Number(original), JSON numeric round-trip, then String. Exact binary64 integer and JSON string round-trip are separate outputs.",
    "limits": "This runtime path is measured separately from spreadsheet import."
  },
  "crm": {
    "status": "Documentation only, as agreed with the user",
    "product": "HubSpot",
    "liveImportExportTest": false,
    "note": "No CRM portal, production account, live contact or payment data was used."
  }
}