Harden report output publication

docs/operations.md

@@ -40,7 +40,11 @@ Weatherreporter validates the final output filename before prompt inspection or
 weather collection. A valid long filename is published through a short,
 same-directory temporary sibling, so temporary naming does not shorten the
 operator-selected destination. A rejected filename does not create a missing
-parent directory.
+parent directory. The final destination itself must be absent or a regular
+file: symlinks, directories, named pipes, sockets, and other special objects
+are rejected before prompt inspection or weather collection. The destination is
+checked again immediately before the atomic replacement; cancellation or a
+deadline at that point leaves the prior report unchanged and skips notification.
 
 `SIGINT` and `SIGTERM` request orderly cancellation of an active action. The
 command lets cancellation and related cleanup finish before it exits; use the