Ethan has 400+ custom tools in ~/.local/bin and no way to know which ones are actually load-bearing before he edits or reaps one. This generates a weekly e-ink card showing, for the 10 tools touched in the last 7 days, exactly who calls them — systemd units, crontabs, other scripts, and Claude hooks — so a 'small edit' never silently breaks a daemon chain again.
Create ~/.local/bin/tool-blast-radius (bash, ~80 lines). 1) `find ~/.local/bin -maxdepth 1 -type f -mtime -7 -printf '%T@ %f\n' | sort -rn | head -10` for recently-edited tools. 2) For each name, grep for callers across four surfaces: `grep -rlF "$name" ~/.config/systemd/user/*.{service,timer}`, `crontab -l`, `grep -rlF "$name" ~/.local/bin --exclude="$name"`, and `grep -rlF "$name" ~/.claude/settings.json ~/.claude/hooks 2>/dev/null`. 3) Emit markdown: tool name, mtime, caller count, and a RISK tag (0 callers = 'orphan — reap candidate', 3+ = 'load-bearing — test before edit'). Cross-reference orphans against existing tool-graveyard-reaper output so the two agree. 4) Write to ~/Tablet/cards/blast-radius-$(date +%F).md for stylus annotation, and pipe the summary through the existing `commit-whisper-dispatch` path. 5) Wire a systemd user timer `tool-blast-radius.timer` firing Sundays 07:00, modeled on wcw-goal-loop-cron-tick.service. Add tool-blast-radius.test.sh asserting the orphan/load-bearing classification against a temp fixture dir.