Jev classifier in tandem with the LLM Sentry

- Jev (TypeSafe, direct) triages mode and task type with confidence
- Its call stands at >= 70% on both and no split; otherwise the LLM
  Sentry decides (unsure, split needs subtasks, or Jev down)
- Jev flights obey the same budget, flock cap, timeout and log
- Tests for every path; flight log is nil-safe
- start.command reads TYPESAFE_API_KEY and threshold from .env

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UQnSw4RRWp8uqpj3nsnnXF

flightlog.go

@@ -43,6 +43,9 @@ func OpenFlightLog(path string) (*FlightLog, error) {
 }
 
 func (l *FlightLog) Write(e Event) {
+	if l == nil {
+		return // no log configured (tests, embedded use)
+	}
 	l.mu.Lock()
 	defer l.mu.Unlock()
 	e.Time = time.Now()