feat: polish first-launch onboarding and post-setup permission guidance

Streamline the five-step flow with smarter skip logic, a centered welcome intro, clearer zh copy, keyboard setup detection via the extension, and home tips when permissions are still missing after onboarding completes.

OSGKeyboardExt/KeyboardViewController.swift

@@ -99,6 +99,7 @@ public final class KeyboardViewController: UIInputViewController {
 
     public override func viewWillAppear(_ animated: Bool) {
         super.viewWillAppear(animated)
+        KeyboardSetupBridge.markExtensionAppearance(hasFullAccess: hasFullAccess)
         consumePendingDictationResultIfNeeded()
         refreshDictationProgressStateIfNeeded()
         refreshFlowSessionState()

OSGKeyboardExt/en.lproj/Keyboard.strings

@@ -3,7 +3,7 @@
 "OSGKeyboard" = "OSGKeyboard";
 
 /* Onboarding */
-"onboarding.welcome.subtitle" = "Hold to talk. Release for polished text, in any app.";
+"onboarding.welcome.subtitle" = "Tap the mic to speak, tap again to finish — polished text in any app.";
 "onboarding.enable.title" = "Enable OSGKeyboard";
 "onboarding.enable.step1" = "Settings → General → Keyboard → Keyboards";
 "onboarding.enable.step2" = "Tap “Add New Keyboard…” and choose OSGKeyboard";

OSGKeyboardExt/zh-Hans.lproj/Keyboard.strings

@@ -3,7 +3,7 @@
 "OSGKeyboard" = "OSGKeyboard";
 
 /* Onboarding */
-"onboarding.welcome.subtitle" = "按住说话,松开即得润色文字。";
+"onboarding.welcome.subtitle" = "点按麦克风说话，再点一次结束，文字即出现。";
 "onboarding.enable.title" = "启用 OSGKeyboard";
 "onboarding.enable.step1" = "设置 → 通用 → 键盘 → 键盘";
 "onboarding.enable.step2" = "点击「添加新键盘…」并选择 OSGKeyboard";