Squashed view of the main-merge finals work for the eduxiji push:
- 初赛 submission materials restored (docs, figures-embedded PDFs, front-page README)
- Finals report/deck at prelims-style paths (compressed: 1.5MB + 0.7MB + 初赛 1.3MB)
- Full RGA2/RGA3 driver + /dev/rga, dwmmc busy-wait fix, JPU selftest asset
- Tennis app: real hardware default (uart/pwm actuators, serial, factory,
  odometry compiled into the board build; trace only via --virtual-actuators)
- Standalone figure PNGs removed (embedded in the shipped PDFs; sources kept)