Leave removed copies out of report and trees (closes #173) (#184)

TODO.md

@@ -29,6 +29,11 @@
 Newest first. An entry ends with its date and its issue or branch, where those
 are known.
 
+- `report` and `trees` leave out a copy that was deleted after the scan. Each
+  checks only the copy itself with `lstat`: the file, or the directory at the
+  top of a tree. A group left with one copy is not reported. A missing `scan`
+  operand is still a fatal error (2026-11-11,
+  https://git.eeqj.de/sneak/sfdupes/issues/173)
 - The usage line of `scan` no longer ends in `[flags]`. It is the line
   `README.md` shows under "Subcommands" (2026-11-11,
   https://git.eeqj.de/sneak/sfdupes/issues/169)