nextcloud/install: session-bus override, KWallet existence check, pass REPO vars

- sync_client_software.sh: add system-wide flatpak session-bus override for
  Nextcloud so KWallet D-Bus access works for all users; fix broken compound
  test ([ a || b ] → [ a ] || [ b ])
- user_run.sh: check KWallet entries with hasEntry before writing — skip write
  and print info message when both passwords are already present; remove stale
  commented-out code
- install.sh: forward REPO_URL and REPO_BRANCH into configure.sh environment
  for both the su- and direct-bash invocation paths
- configure.sh: simplify do_configure (user cleanup)

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

system_setup/install.sh

@@ -49,10 +49,10 @@ finish_install() {
     if [[ "${RUN_CONF,,}" == "y" ]]; then
         if [[ -n "$SUDO_USER" && "$SUDO_USER" != "root" ]]; then
             info "Running configure.sh as user '$SUDO_USER'..."
-            su - "$SUDO_USER" -c "DISPLAY='${DISPLAY}' WAYLAND_DISPLAY='${WAYLAND_DISPLAY}' bash '$CONF_SCRIPT'"
+            su - "$SUDO_USER" -c "DISPLAY='${DISPLAY}' WAYLAND_DISPLAY='${WAYLAND_DISPLAY}' REPO_URL='${REPO_URL}' REPO_BRANCH='${REPO_BRANCH}' bash '$CONF_SCRIPT'"
         else
             info "Running configure.sh as root..."
-            bash "$CONF_SCRIPT"
+            REPO_URL="$REPO_URL" REPO_BRANCH="$REPO_BRANCH" bash "$CONF_SCRIPT"
         fi
     else
         echo