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/InsightsView/InsightsView.swift

@@ -9,11 +9,12 @@ import SwiftUI
 
 struct InsightsView: View {
     @AppStorage(UserDefaultsStore.Keys.theme.rawValue, store: GroupUserDefaults.groupDefaults) private var theme: Theme = .system
-    @AppStorage(UserDefaultsStore.Keys.textColor.rawValue, store: GroupUserDefaults.groupDefaults) private var textColor: Color = DefaultTextColor.textColor
     @AppStorage(UserDefaultsStore.Keys.moodTint.rawValue, store: GroupUserDefaults.groupDefaults) private var moodTint: MoodTints = .Default
     @AppStorage(UserDefaultsStore.Keys.moodImages.rawValue, store: GroupUserDefaults.groupDefaults) private var imagePack: MoodImages = .FontAwesome
     @Environment(\.colorScheme) private var colorScheme
 
+    private var textColor: Color { theme.currentTheme.labelColor }
+
     @StateObject private var viewModel = InsightsViewModel()
     @EnvironmentObject var iapManager: IAPManager
     @State private var showSubscriptionStore = false