fix: count cache tokens, honor mid-handler pause, harden tag escaping

- totalTokensForMessage includes cache.read/write (budget undercount fix)
- activeGoal() helper makes /goal pause mid-handler stop next auto-continue
- escapeGoalText neutralizes opening structural tags (injection hardening)
- smoke script runs with persistState:false
- document warn* options; bump 0.1.13 -> 0.1.14