robot/: point the old-sketch references to 2019-teensy-nrf24/Hexapod_Teensy

Comments in Config.h and the README referred to LEGACY/, which is folded into the generation folders. Also 'from the repo root' -> 'from the 2026-current folder'. Comment and documentation changes only; approved by the owner.

2026-current/robot/Config.h

@@ -56,7 +56,7 @@ struct ServoCal {
   int16_t us_min, us_max;
 };
 
-// Built from the old robot sketch (LEGACY/Hexapod_Teensy/config.h), which
+// Built from the old robot sketch (2019-teensy-nrf24/Hexapod_Teensy/config.h), which
 // drove each servo with PWMServo: a command of 0..180 maps linearly onto
 // min..max microseconds (servoMin/servoMax + servoCallibration trim). The
 // command for a joint angle is  zero + dir * joint_deg + offset, where
@@ -111,7 +111,7 @@ constexpr float CONTROL_HZ = 60.0f;
 // ---- Radio (nRF24L01) ----
 // Address/channel/data rate/PA/payload size live in shared/HexapodProtocol
 // so the robot and remote can't drift apart. Only this board's wiring is here.
-// From the old robot sketch (LEGACY/Hexapod_Teensy/Nrf.h): SPI on MOSI 11 /
+// From the old robot sketch (2019-teensy-nrf24/Hexapod_Teensy/Nrf.h): SPI on MOSI 11 /
 // MISO 12 with SCK moved to its alternate pin 14 (Teensy 3.x), so pin 13
 // stays free.
 constexpr uint8_t RADIO_CE_PIN     = 39;