kwallet: remove ExecStop, stop old unit in user_run.sh instead

ExecStop on the user service caused an unmount race: it fired
asynchronously after logout while the next login's install.sh had
already remounted the wallet, then unmounted it again leaving
kwalletd6 without its wallet directory.

install.sh already handles umount/remount at login start, so no
ExecStop is needed. On gocryptfs systems the wallet becomes
inaccessible at logout naturally when ~/data is unmounted.

user_run.sh now explicitly stops any leftover kwalletd6-logon unit
from a previous session before creating a new one, avoiding the
systemd-run unit-name-conflict failure.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client_software/0010_kwallet/user_run.sh

@@ -18,12 +18,11 @@ if [[ -z $(wmctrl -m | grep "KWin") ]]; then
 fi
 
 #Restart the service
-WALLETPATH_CFG="${HOME}/.local/share/kwalletd"
+# Stop any leftover unit from a previous session before creating a new one
+systemctl --user stop kwalletd6-logon.service 2>/dev/null || true
 systemd-run --user --unit=kwalletd6-logon \
     --property=RemainAfterExit=yes \
     --property=SuccessExitStatus=1 \
-    --property=Before=gocryptfs-home.service \
-    --property="ExecStop=/usr/bin/sudo /usr/bin/umount -l ${WALLETPATH_CFG}" \
     kwalletd6 >${TEMPDIR}/kwalletd6.log 2>&1 &
 sleep 1