refactor: rimuove feature Auto-Calibrazione (tab + endpoint + job runner)

Elimina il flusso di acquisizione griglia automatica: tab GUI, modulo
autocal3d.js, AutoRunner/auto_job, e gli endpoint /auto/* + /auto_grid.
La calibrazione resta operabile via sample manuali + /solve.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/diagnostic3d.js

@@ -431,11 +431,6 @@ class G1Viewer {
   }
 }
 
-// Expose the viewer class so other modules (Auto-Calibrazione) can
-// instantiate a second canvas over the same URDF pipeline.
-export { G1Viewer };
-
-
 // ---- Boot and expose global hook. ----
 
 const canvas = document.getElementById('diag3dCanvas');