Reflection follow-up: rewrite missing substrate file op-read

Missing path: ~/bin/op-read Referenced in: FLEET-TOOLS.md line 21 as a shorthand wrapper: ~/bin/op-read "op://Fleet Secrets/<item>/<field>" Presumed contents: A short shell script (shim) that runs HOME=/var/tmp/op-agent op read "$@" to bypass the desktop daemon check. FLEET-TOOLS.md documents it as the canonical shorthand. ~/bin/ directory exists and has other scripts (gh-fleet-token.sh, healthcheck.sh etc.).