Fix the install pipeline and an idle-lock startup race

The initial package list was quoted into a single bogus dnf argument
and every dnf error was discarded, so a fresh install silently skipped
most of it. Two package lists were never wired into the pipeline at
all, and change-settings ran before install-packages, so the vicinae
theme step was permanently skipped. Fixed the ordering, the quoting,
and stopped swallowing errors.

Separately, hypridle could start with its WAYLAND_DISPLAY condition
unmet if it raced the env-publish call, silently never starting --
and it's the only listener for the logind Lock signal. Made the start
wait on the environment synchronously. panama-idle also wrote its
generated config to a fixed temp path with no locking, so concurrent
applies could interleave into a corrupt file; switched to mktemp plus
an atomic mv.

Claude-Session: https://claude.ai/code/session_01E6TJUAh41HaP25MVHWkhRZ

setup/scripts/link-dotfiles

@@ -63,6 +63,12 @@ for dir in "${dirs[@]}"; do
   if [ -d "$CONFIG/$dir" ]; then
     mv "$CONFIG/$dir" "$PANAMA_OLD/$dir"
     log "Moved existing $dir config to $PANAMA_OLD/$dir"
+  # A regular file at this path (not a directory, not a symlink) is missed by
+  # the guards above, so `ln -s` below would fail with "File exists" -- back
+  # it up the same way.
+  elif [ -f "$CONFIG/$dir" ]; then
+    mv "$CONFIG/$dir" "$PANAMA_OLD/$dir"
+    log "Moved existing $dir file to $PANAMA_OLD/$dir"
   fi
 
   # Create symlink