Remove purple color, add perpendicular gate approach, fix regulator, integrate...

Remove purple color, add perpendicular gate approach, fix regulator, integrate smach_viewer and pool_mapper

- Remove purple from color segmentation, state machine, and launch files
- Fix anti-regulation bug in PP-regulator (sign correction)
- Add perpendicular gate approach via gain scheduling in move_to_gate
- Rename delta_time to gate_delta_time to avoid YAML key collision
- Add smach_viewer and pool_mapper integration to main launch
- Remove image_transport republish nodes (Unity sends compressed directly)
- Fix thruster remapping in movement launch

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>