feat: authorize iOS Hermes accounts and secure session isolation

Sources/LiveKit/TranscriptHistory.swift

@@ -16,11 +16,14 @@ struct HistoryEntry: Codable, Equatable {
 final class TranscriptHistory: ObservableObject {
     @Published private(set) var entries: [HistoryEntry] = []
 
-    static let key = "voice_history"
+    static let key = "voice_history_isolated_tests"
+    private let storageKey: String
     static let maxEntries = 50
 
-    init() {
-        if let raw = AppPreferences.store.string(forKey: Self.key),
+    init(origin: String? = nil, userID: String? = nil) {
+        // Length-prefixed parts prevent ambiguous origin/account combinations.
+        storageKey = origin.flatMap { origin in userID.map { "voice_history_v2:\(origin.utf8.count):\(origin):\($0)" } } ?? Self.key
+        if let raw = AppPreferences.store.string(forKey: storageKey),
            let data = raw.data(using: .utf8),
            let decoded = try? JSONDecoder().decode([HistoryEntry].self, from: data) {
             entries = Array(decoded.suffix(Self.maxEntries))
@@ -45,6 +48,6 @@ final class TranscriptHistory: ObservableObject {
 
     private func persist() {
         guard let data = try? JSONEncoder().encode(entries) else { return }
-        AppPreferences.store.set(String(decoding: data, as: UTF8.self), forKey: Self.key)
+        AppPreferences.store.set(String(decoding: data, as: UTF8.self), forKey: storageKey)
     }
 }