Qualify the Traffic render-hold note for failed loads

A failed load leaves no hold only when no animated content is retained.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

docs/CURRENT-STATE.md

@@ -14,7 +14,7 @@ existing batch size and one bounded upstream chunk. Larger requests return HTTP
 413 before disk-cache loading or upstream work; malformed coordinates remain 400.
 The browser continues to split larger workloads into sequential 64-point requests.
 
-Traffic holds continuous rendering only while enabled with animated dots or a pulsing jam heat-line. Empty, failed, and high-altitude views release the hold; population admission reacquires it and resets animation time. Clear, disable, and destroy also release it. Retained fading dots keep animation alive until they are removed.
+Traffic holds continuous rendering only while enabled with animated dots or a pulsing jam heat-line. Empty and high-altitude views release the hold. A failed load leaves no hold only when no animated content is retained: if an earlier load succeeded, ingestion keeps its animated points and the hold stays. Population admission reacquires the hold and resets animation time. Clear, disable, and destroy also release it. Retained fading dots keep animation alive until they are removed. When the last point leaves mid height correction, the correction is settled at once, before the hold is released, so it cannot keep the layer reporting loading.
 
 Shared distance checks use `src/geoDistance.js` with `{ lat, lon }` points and
 the IUGG mean spherical Earth radius, 6371.0088 km. `greatCircleKm` is