- Add n4 parameter to control server, LED bar receiver, and test script
- Create segmented_movement pattern with alternating forward/backward movement
- Pattern supports n1 (segment length), n2 (spacing), n3 (forward speed), n4 (backward speed)
- Fix test script to send all messages instead of just the first one
- Add segmented_movement to patterns_needing_params for proper parameter transmission
- Pattern intelligently handles all cases: alternating, forward-only, backward-only, or static
- Implements repeating segments with configurable spacing across LED strip
