Update Neon colors and show color circles in theme picker

- Update NeonMoodTint to use synthwave colors matching Neon voting style
  (cyan, lime, yellow, orange, magenta)
- Replace text label with 5 color circles in theme preview Colors row
- Remove unused textColor customization code and picker views
- Add .id(moodTint) to Month/Year views for color refresh
- Clean up various unused color-related code

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Shared/Views/ImagePickerGridView.swift

@@ -12,8 +12,9 @@ struct ImagePickerGridView: View {
     @Environment(\.presentationMode) var presentationMode
     @State var column = Array(repeating: GridItem(.flexible(), spacing: 10), count: 7)
     let pickedImageClosure: ((CustomWidgeImageOptions) -> Void)
-    @AppStorage(UserDefaultsStore.Keys.textColor.rawValue, store: GroupUserDefaults.groupDefaults) private var textColor: Color = DefaultTextColor.textColor
-    
+
+    private var textColor: Color { theme.currentTheme.labelColor }
+
     let imageOptions = CustomWidgeImageOptions.allCases.sorted(by: {
         $0.rawValue < $1.rawValue
     })