Fold LEGACY into the generation folders

The LEGACY copies of HexapodRobot, Hexapod_NEW, Hexapod_Teensy and the old remote sketch were identical to the imported repos and are removed. The old Nextion design moves to 2019-teensy-nrf24/remote-nextion/, the 2019 remote case files to 2019-teensy-nrf24/remote-case/. Paths in CLAUDE.md, READMEs, remote/ comments, sim/build.ps1, the Unity DLL message and .vscode/settings.json now point to the new places. robot/ is not touched (its CLAUDE.md asks to check with the owner first).

2026-current/.vscode/settings.json

@@ -1,3 +1,3 @@
 {
-    "cmake.sourceDirectory": "D:/Claude/Hexapod/sim"
+    "cmake.sourceDirectory": "${workspaceFolder}/sim"
 }