feat: TypeWhisper Flow sessions, Phase 4 UX, and GitHub Pages privacy site

Migrate keyboard dictation to continuous Flow sessions with auto-start,
tap-to-toggle recording, 60s countdown, five-step onboarding, and App Group
IPC. Add docs/ GitHub Pages site with en/zh privacy policy for App Store compliance.

OSGKeyboardShared/Models/EngineServiceLabel.swift

@@ -0,0 +1,26 @@
+// EngineServiceLabel.swift
+// OSGKeyboard · Shared
+//
+// Human-readable summary of the active engine / AI provider for UI hints.
+
+import Foundation
+
+public enum EngineServiceLabel {
+    public static func summary(
+        engineMode: String,
+        providerId: String,
+        model: String
+    ) -> String {
+        let isChinese = Locale.preferredLanguages.first?.hasPrefix("zh") == true
+        let prefix = isChinese ? "当前：" : "Active: "
+        if engineMode == "local" {
+            return isChinese
+                ? "\(prefix)本地引擎 · Apple SpeechAnalyzer"
+                : "\(prefix)On-device · Apple SpeechAnalyzer"
+        }
+        let provider = LLMProvider.provider(id: providerId)
+        let trimmedModel = model.trimmingCharacters(in: .whitespacesAndNewlines)
+        if trimmedModel.isEmpty { return "\(prefix)\(provider.name)" }
+        return "\(prefix)\(provider.name) · \(trimmedModel)"
+    }
+}