secrets-init: store a piped secret without a final newline

`pbpaste | ssh petrolyst /root/secrets-init.sh keycloak-secret` sends the
secret without a trailing newline. read then sets the value but returns
non-zero, and set -e ended the script silently before storing it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

host/secrets-init.sh

@@ -44,7 +44,9 @@ case ${1:-all} in
       IFS= read -rs value
       echo >&2
     else
-      IFS= read -r value
+      # `pbpaste | ...` sends no final newline: read then still sets value but
+      # fails, which set -e would turn into a silent exit.
+      IFS= read -r value || true
     fi
     value=$(printf '%s' "$value" | tr -d '[:space:]')
     [ -n "$value" ] || die "empty secret"