tests: controllo statico che le etichette dei tasti ci stiano

Le etichette si leggono da MainPage.qml e dal catalogo, la geometria dai numeri
misurati sul telefono: se un'etichetta si allunga (o l'icona si ingrandisce) il
controllo lo segnala prima della build. Su "Commands" fallisce, come deve.

README.md

@@ -148,6 +148,7 @@ milliseconds and name the file they are unhappy about:
 ```sh
 python3 tests/qml_check_bindings.py qml   # no property assigned twice in one object
 python3 tests/qml_focus_check.py          # a tap opens only the object it touched
+python3 tests/label_fit_check.py          # quick-action labels fit the button
 ```
 
 ## Status
@@ -248,6 +249,7 @@ tests/core_test.cpp     core checks (headless)
 tests/ui_contract_check.py  QML keys vs bridge keys (bridge must be running)
 tests/qml_check_bindings.py duplicate property assignments in the QML
 tests/qml_focus_check.py   a tap opens only that object's settings
+tests/label_fit_check.py   quick-action labels fit next to the icon (measured on a phone)
 bridge/                 local HTTP bridge -> see bridge/README.md
 translations/           harbour-aira-it.ts (English is the source language)
 docs/PIANO.md           project plan and decisions (Italian)