Bug fix from a production screenshot: the statusline said ✓ safe to close while the mentor's verification suite ran in a session background shell — builder locks were the segment's whole model of work-in-flight, but session shells die with the session, so they're exactly what "safe to close" is about. The segment now detects live Bash-tool shells of the current session (via the shell-snapshots fingerprint, which cleanly excludes persistent MCP server wrappers) and shows ⚙ session work running — closing kills it before ever claiming safe. Priority: 🔨 building → ⚙ session work → 💀 last build died → ✓ safe to close. Reinstall or re-run /ss-status:install to refresh the installed scripts.