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>

src/presa_mano/main.py

@@ -101,7 +101,7 @@ def index() -> HTMLResponse:
     idx = WEB_DIR / "index.html"
     html = idx.read_text(encoding="utf-8")
     # Cache-bust app.js and style.css with their mtime so a rebuild forces refetch.
-    for name in ("app.js", "autocal3d.js", "servo.js", "style.css"):
+    for name in ("app.js", "servo.js", "style.css"):
         f = WEB_DIR / name
         if f.exists():
             v = int(f.stat().st_mtime)