Initial import: robot firmware + PlatformIO two-env scaffold

Robot-side firmware (Teensy 4.0) imported unchanged as extracted.
platformio.ini defines [env:robot] (teensy40) and [env:remote]
(teensy41); scripts/select_src_dir.py points each env at its own
sketch folder so robot/ and remote/ stay Arduino-style sketches.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2026-current/robot/ServoDriver.h

@@ -0,0 +1,9 @@
+#pragma once
+#include "Kinematics.h"
+
+class ServoDriver {
+public:
+  void begin();                                       // attach all servos
+  void relaxAll();                                     // detach all servos - call when disarming
+  void writeLeg(int leg_index, const JointAngles& angles);
+};