Normalize selection keys

When selecting a “preferred” item (via find, filter, pagination anchors, etc.) or deciding based on a computed threshold, ensure two things: 1) Compare like with like: normalize/parse inputs so the keys you compare are in the same canonical form. 2) Use explicit priority + fallback: run a primary search first; only if it yields nothing should you consult a fallback source. Avoid making fallback evidence primary.

Practical checklist:

• If settings/identifiers may be encoded (e.g., authType:modelId), always decode/resolve to the same shape before comparing to stored objects.
• If multiple event sources can provide the anchor/marker, implement a 2-pass selection: (a) search preferred sources, (b) if none found, use fallback.
• For threshold/budget calculations that depend on layout, include all relevant contributing elements (missing siblings/gaps can flip thresholds).

Code pattern (key normalization + prioritized fallback):

// 1) Normalize first (so comparisons match)
const normalized = isCompactionMode
  ? resolveModelId(settings?.merged?.compactionModel?.trim() ?? '')
  : undefined;

// 2) Primary then fallback
const preferred = (() => {
  // primary: use the most reliable/expected source(s)
  const primary = normalized
    ? availableModelEntries.find(({ authType, model }) =>
        authType &&
        authType === normalized.authType &&
        model.id === normalized.modelId
      )
    : undefined;

  if (primary) return primary;

  // fallback: weaker/secondary match only if primary failed
  return availableModelEntries.find(({ model }) => model.id === normalized?.modelId);
})();

Apply this same approach to anchor selection and transcript pagination: prefer session_update-derived ids first; only if absent should you use the history_truncated marker id.