Drop the tick from drop-lists; the row is already tinted

The selected row carries selection-background-color, so a checkmark repeats
what the colour says — and in a combo as wide as "VN" it repeated it on top of
the letters. A combo's default delegate paints menu-style, which is where the
glyph comes from; a plain QStyledItemDelegate paints item-view style, which has
none. widen_popup does both jobs now, so it is tidy_popup.

check_combo_popup additionally requires the delegate to be the plain one and the
stylesheet to still tint the current row — removing the delegate line fails it.

21/21 checkers pass.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

ui/widgets.py

@@ -162,17 +162,25 @@ def guard_wheel(root: QWidget) -> None:
         w.installEventFilter(_wheel_guard)
 
 
-def widen_popup(combo) -> None:
-    """Give a drop-list room for its text AND the tick beside the current item.
+def tidy_popup(combo) -> None:
+    """Make a drop-list show its options and nothing else.
 
-    macOS draws a checkmark against the selected row; Windows does not. A combo
-    only as wide as "VN" therefore looked fine here and had its two letters
-    covered there. The popup inherits the combo's width unless told otherwise,
-    so measure what has to fit and say so.
+    Two platform habits to undo. macOS marks the current row with a checkmark,
+    drawn by the menu-style delegate a combo gets by default; the row is already
+    tinted by selection-background-color, so the tick says nothing twice and, in
+    a combo only as wide as "VN", covered the letters it was marking. Handing
+    the view a plain QStyledItemDelegate switches it to item-view painting,
+    where no such glyph exists.
+
+    And the popup inherits the combo's width unless told otherwise, which had
+    the project and provider names cut off here regardless of platform. So
+    measure the longest item — plus an indicator's worth of room, in case a
+    style still draws one — and set that as the view's minimum.
     """
-    from PySide6.QtWidgets import QStyle
+    from PySide6.QtWidgets import QStyle, QStyledItemDelegate
 
     view = combo.view()
+    combo.setItemDelegate(QStyledItemDelegate(combo))
     fm = view.fontMetrics()
     longest = max((fm.horizontalAdvance(combo.itemText(i))
                    for i in range(combo.count())), default=0)