macOS: textSetColor is a no-op on a Text label (padding cell bakes attributedStringValue, overriding setTextColor:) #10856

Summary

On macOS, textSetColor has no visible effect on a Text() label. The label always renders in the default labelColor (white in dark appearance), regardless of the color passed.

Cause

Text() creates an NSTextField.labelWithString (crates/perry-ui-macos/src/widgets/text.rs), then install_label_cell (crates/perry-ui-macos/src/widgets/padding.rs:208) captures and re-sets the field's attributedStringValue (line 219). An NSTextField with an attributedStringValue ignores setTextColor: — the attributed string's baked-in color attribute (the default labelColor) wins. So perry_ui_text_set_color → setTextColor: is silently overridden.

Reproduce

• macOS, Perry 0.5.1622 (local build), Darwin 25.6.0 arm64.
• const t = Text("hi"); textSetFontSize(t, 40); textSetColor(t, 1, 0, 0, 1) on a white background.
• The label renders in the default color (white in dark appearance / invisible on white), not red. A pure-red, -green, -blue label all render white on a dark background — the color argument is ignored entirely.

Expected

textSetColor colors the label.

Workaround

Re-set the string after coloring (textSetString(widget, text)), which replaces the stale attributedStringValue with a plain stringValue, so textColor applies.

Suggested fix

Have set_color (and the other text setters) update the attributed string's color attribute when the label carries an attributedStringValue, or have install_label_cell not bake a color attribute into it.