Creates a new InterventionEngine with the given threshold config.
Inactivity, error repetition, and time warning thresholds.
Evaluates all trigger rules against the current session signals.
Current state of the tutor FSM.
Most recent WorkAnalysis, or null if none yet.
Seconds since session start.
Seconds since the student last produced any input.
The highest-priority InterventionPlan, or null if no triggers fired.
Records that an intervention was delivered so the engine can avoid re-triggering the same plan immediately.
The intervention plan that was executed.
Evaluates intervention triggers and produces prioritised plans.