Add ADG936BCPZ, OSD32MP157F-1G-BAA, TPS22965DSGR, AXP2101; add programmatic API and usage guide

- scripts/mikilab_lib.py / mikilab_cli.py: typed Python API + JSON CLI
  for add/update/remove/query, for other apps to integrate without
  shelling out to add_component.py
- lib_common.py/import_component.py/import_batch.py: regenerate
  sym-lib-table.global/fp-lib-table.global on every mutating call, not
  just the project-local tables
- scripts/find_missing_3d_models.py: lists components with no 3D model
  and search links to fill the gap
- docs/GUIDA_USO.md: practical Italian usage guide (companion to README.md)
- checkup fixes: removed orphan duplicate footprint
  footprints/other/CP_20_1_ADI.kicad_mod, and a dangling
  ${easyeda2kicad}/tmp 3D model reference in AXP2101's footprint that
  pointed at a file that never existed on disk

scripts/import_batch.py

@@ -110,6 +110,7 @@ def main() -> int:
 
     sym_entries = lc.write_sym_lib_table(ROOT)
     fp_entries = lc.write_fp_lib_table(ROOT)
+    lc.write_global_tables(ROOT)
 
     print(f"Batch import from {source}")
     print()
@@ -118,6 +119,12 @@ def main() -> int:
 
     print()
     print(f"Regenerated sym-lib-table ({len(sym_entries)} libraries) and fp-lib-table ({len(fp_entries)} libraries)")
+    print("Regenerated sym-lib-table.global and fp-lib-table.global")
+    print(
+        "NOTE: if this library is registered globally in KiCad (README.md section 1), "
+        "also re-run the merge step to update ~/Library/Preferences/kicad/*/sym-lib-table "
+        "and fp-lib-table, or new components will not show up there."
+    )
 
     ok = sum(1 for _, status, _ in results if status == "OK")
     errors = sum(1 for _, status, _ in results if status == "ERROR")