feat(06-02): THE pure D-04 guidance state machine + forward-only projection + named constants (GREEN)
- createGuidanceSession + stepGuidance: the thresholds+grace reroute machine
(idle/on_route/off_route/rerouting/resuming/no_reroute) with accuracy-aware
threshold max(35, 2xacc) capped 100, 3-consecutive-fixes + grace gates,
missed-turn shortened grace (3s), storm guard with off_route re-request
after expiry, honest no_reroute degradation
- projectAlongRoute: forward-only cos(lat)-scaled projection, cumulative
remaining (D-07), haversineM deviation (one distance authority)
- once-per-edge D-08 effect stream: approach 300 m / maneuver impact /
arrive + arrival at 25 m (D-14); reroute-applied re-arms, measures against
the NEW model only (Pitfall 6)
- replay suite R1-R12 green: corridor/excursion/missed-turn/jitter drives,
storm guard mechanics, self-heal, structural purity gate; 88/88 web tests