feat: tip IAP, commercial GitHub Pages, and App Store screenshots

Add optional StoreKit support tip (features stay free), redesign the
landing page with zh/en + light/dark and product shots, and ship
iPhone/iPad/Mac App Store screenshot sets.

OSGKeyboard/Views/HomeView.swift

@@ -174,7 +174,7 @@ struct HomeView: View {
 
     private var wideHeroHeader: some View {
         VStack(alignment: .leading, spacing: Spacing.xs) {
-            Text("home.wide.tagline")
+            Text("onboarding.welcome.tagline")
                 .font(.system(size: 30, weight: .semibold))
                 .foregroundStyle(palette.textPrimary)
                 .lineLimit(2)

OSGKeyboard/Views/OnboardingView.swift

@@ -370,6 +370,17 @@ private struct WelcomePage: View {
     @State private var logoAppeared = false
 
     var body: some View {
+        ZStack {
+            SonicParticleField(focalPoint: UnitPoint(x: 0.5, y: 0.42))
+                .frame(maxWidth: .infinity, maxHeight: .infinity)
+                .allowsHitTesting(true)
+
+            welcomeContent
+        }
+        .frame(maxWidth: .infinity, maxHeight: .infinity)
+    }
+
+    private var welcomeContent: some View {
         VStack(spacing: 0) {
             Spacer()
 
@@ -398,6 +409,7 @@ private struct WelcomePage: View {
             Spacer()
         }
         .frame(maxWidth: .infinity, maxHeight: .infinity)
+        .allowsHitTesting(false)
     }
 }
 

OSGKeyboard/Views/SettingsView.swift

@@ -39,6 +39,9 @@ struct SettingsView: View {
                 palette.background.ignoresSafeArea()
                 ScrollView {
                     VStack(spacing: Spacing.md) {
+                        if presentation == .tab {
+                            SupportDeveloperSection(language: config.uiLanguage)
+                        }
                         languageAndPolishSection
                         dictionaryAndPolishSection
                         flowSessionSection

OSGKeyboard/en.lproj/Localizable.strings

@@ -335,7 +335,6 @@
 "home.flow.startShort" = "Start";
 "home.preview.label" = "Try typing";
 "home.preview.placeholder" = "Tap to type and test…";
-"home.wide.tagline" = "Voice dictation, anywhere.";
 "home.wide.tagline.subtitle" = "Switch to any app and tap the keyboard mic to dictate.";
 "home.wide.mode.cloud" = "Cloud";
 "home.wide.mode.local" = "On-device";

OSGKeyboard/zh-Hans.lproj/Localizable.strings

@@ -334,7 +334,6 @@
 "home.flow.startShort" = "开启";
 "home.preview.label" = "输入测试";
 "home.preview.placeholder" = "点这里试试键盘";
-"home.wide.tagline" = "随处语音听写";
 "home.wide.tagline.subtitle" = "切换到任意 App，点键盘麦克风即可听写。";
 "home.wide.mode.cloud" = "云端";
 "home.wide.mode.local" = "本机";