fix(cyclones): distinguish deliberate clears from feed eviction

changelog.d/847-cyclone-shared-selection.md

@@ -1,4 +1,4 @@
 - Explicit cyclone selections publish only the currently selected NHC/CPHC
-  storm into shared context. Switching storms evicts the previous identity
-  instead of leaving stale coordinates active (kvnloo, #847; reviewed by
-  quanticsoul4772).
+  storm into shared context. Switching storms removes the previous identity
+  without a false eviction event. Deliberate clears remain distinct from feed
+  disappearance (kvnloo, #847; reviewed by quanticsoul4772).