Offer Claude sign-in from failed sessions

app/androidApp/src/main/kotlin/com/example/aiapp/Events.kt

@@ -192,6 +192,8 @@ sealed class SessionEvent {
      */
     data class LimitReached(val resetsAt: Double?) : SessionEvent()
 
+    data class AuthenticationRequired(val message: String) : SessionEvent()
+
     data class Error(val message: String) : SessionEvent()
 
     /**
@@ -303,6 +305,8 @@ fun parseSeqEvent(json: String): SeqEvent {
                 SessionEvent.LimitReached(
                     if (body.has("resetsAt")) body.getDouble("resetsAt") else null
                 )
+            "authenticationRequired" ->
+                SessionEvent.AuthenticationRequired(body.getString("message"))
             "error" -> SessionEvent.Error(body.getString("message"))
             else -> SessionEvent.Unknown(type)
         }
@@ -319,6 +323,19 @@ fun parseSeqEvent(json: String): SeqEvent {
  */
 fun sessionWorking(state: String): Boolean = state == "running" || state == "compacting"
 
+/** Whether the latest events still say this session needs an explicit provider login. */
+internal fun authenticationPromptAfter(open: Boolean, event: SessionEvent): Boolean =
+    when (event) {
+        is SessionEvent.AuthenticationRequired -> true
+        // A later provider response proves an older authentication failure in a replayed page is
+        // no longer current. Without this, one old failure reopened sign-in after every later
+        // successful turn.
+        is SessionEvent.AssistantText,
+        is SessionEvent.AssistantTextFinal,
+        is SessionEvent.ToolStart -> false
+        else -> open
+    }
+
 /**
  * The context after [event], given what it was before.
  *