Function reportLoadOutcome

reportLoadOutcome(
    failedPaths: readonly string[],
    registeredPaths: readonly string[],
    failureReasons?: readonly string[],
): LoadOutcome
Report the outcome of a scene load exactly once, proportionately to how bad it was.
- clean → the historical success log, text unchanged (an E2E smoke test matches it, and it is the signal log filters key on).
- partial → one aggregate warning. No user-facing notification: the per-node failures already logged, and the data-loading monitor's failed-loads banner is the standing surface.
- total → an error log plus a toast, because nothing rendered and the caller cannot tell: loadScene resolves successfully either way.
Parameters
- failedPaths: readonly string[]
  Scene paths whose load failed.
- registeredPaths: readonly string[]
  Scene paths that registered a loader — the attempted set. A failed lazy LOD level may fail WITHOUT registering, so grade totality against this set, not a count.
- failureReasons: readonly string[] = []
  Recorded failure messages in encounter order.
Returns LoadOutcome
- Defined in src/data/scene-loader/loaders/failure-report.ts:69