fix(#688): route expired auth sessions to sign-in (#689)

* fix(#688): route expired auth sessions to sign-in

Adopt global 401 latch, WS disconnect, and Back/profile guards.

* chore: clean up formatting noise

* fix(ktlint): reorder imports to place java and kotlinx at end

* fix(ktlint): place java.io.IOException at end of imports

* test: fix NavBackStack type parameter in AuthenticationRoutingTest

* test: add AuthSessionState tests to AuthLoginViewModelTest

* fix(ktlint): fix import order in AuthLoginViewModelTest

app/src/main/java/com/m57/hermescontrol/Navigation.kt

@@ -28,6 +28,7 @@ import androidx.compose.material3.Text
 import androidx.compose.material3.rememberDrawerState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
@@ -43,6 +44,7 @@ import androidx.navigation3.runtime.NavKey
 import androidx.navigation3.runtime.entryProvider
 import androidx.navigation3.ui.NavDisplay
 import com.m57.hermescontrol.data.local.AuthManager
+import com.m57.hermescontrol.data.local.AuthSessionState
 import com.m57.hermescontrol.data.ws.ConnectionStatus
 import com.m57.hermescontrol.data.ws.HermesWsClient
 import com.m57.hermescontrol.theme.LocalHermesStatusColors
@@ -132,6 +134,14 @@ private fun appEntryProvider(
 
 @Composable
 fun MainNavigation(sessionId: String? = null) {
+    val signInRequired by AuthSessionState.signInRequired.collectAsState()
+    LaunchedEffect(signInRequired) {
+        if (signInRequired) {
+            HermesWsClient.disconnect()
+            NavigationController.resetTo(AuthLoginScreen)
+        }
+    }
+
     val token by AuthManager.tokenFlow.collectAsState()
     val hasToken = !token.isNullOrBlank()
     val startScreen: NavKey = if (hasToken) ChatScreen else LandingScreen

app/src/main/java/com/m57/hermescontrol/NavigationController.kt

@@ -2,6 +2,7 @@ package com.m57.hermescontrol
 
 import androidx.navigation3.runtime.NavBackStack
 import androidx.navigation3.runtime.NavKey
+import com.m57.hermescontrol.data.local.AuthSessionState
 
 /**
  * Central navigation controller with deduplication guard.
@@ -58,11 +59,24 @@ object NavigationController {
      */
     fun goBack(fallback: NavKey = ChatScreen) {
         val stack = backStack ?: return
+        val effectiveFallback =
+            if (AuthSessionState.signInRequired.value && (fallback == ChatScreen || isPrimaryScreen(fallback))) {
+                LandingScreen
+            } else {
+                fallback
+            }
         if (stack.size > 1) {
             stack.removeLastOrNull()
+            if (AuthSessionState.signInRequired.value &&
+                stack.lastOrNull() != AuthLoginScreen &&
+                stack.lastOrNull() != LandingScreen
+            ) {
+                stack.clear()
+                stack.add(LandingScreen)
+            }
         } else if (stack.size == 1) {
             stack.clear()
-            stack.add(fallback)
+            stack.add(effectiveFallback)
         }
     }
 }

app/src/main/java/com/m57/hermescontrol/data/local/AuthSessionState.kt

@@ -0,0 +1,31 @@
+package com.m57.hermescontrol.data.local
+
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+/**
+ * Single source of truth for app-wide auth session expiry latch.
+ * When a REST call returns 401 (AuthExpired), [requireSignIn] is invoked,
+ * triggering central navigation reset to [AuthLoginScreen] and WS disconnect.
+ */
+object AuthSessionState {
+    private val _signInRequired = MutableStateFlow(false)
+    val signInRequired: StateFlow<Boolean> = _signInRequired.asStateFlow()
+
+    fun requireSignIn() {
+        _signInRequired.value = true
+    }
+
+    fun markAuthenticated() {
+        _signInRequired.value = false
+    }
+
+    fun clearSignInRequired() {
+        _signInRequired.value = false
+    }
+
+    fun resetForTest() {
+        _signInRequired.value = false
+    }
+}

app/src/main/java/com/m57/hermescontrol/data/remote/NetworkResult.kt

@@ -1,5 +1,6 @@
 package com.m57.hermescontrol.data.remote
 
+import com.m57.hermescontrol.data.local.AuthSessionState
 import kotlinx.coroutines.delay
 import kotlinx.serialization.json.jsonObject
 import kotlinx.serialization.json.jsonPrimitive
@@ -90,6 +91,7 @@ fun jitteredBackoff(baseMs: Long): Long {
 
 suspend inline fun <reified T> safeApiCall(
     retries: Int = 2,
+    reportAuthExpiry: Boolean = true,
     crossinline call: suspend () -> Response<T>,
 ): NetworkResult<T> {
     var lastException: IOException? = null
@@ -118,7 +120,11 @@ suspend inline fun <reified T> safeApiCall(
                     delay(backoff)
                     continue
                 }
-                return NetworkResult.Failure(mapHttpError(code, errorBody))
+                val failure = NetworkResult.Failure(mapHttpError(code, errorBody))
+                if (reportAuthExpiry && failure.error is NetworkError.AuthExpired) {
+                    AuthSessionState.requireSignIn()
+                }
+                return failure
             }
         } catch (e: IOException) {
             lastException = e

app/src/main/java/com/m57/hermescontrol/ui/authlogin/AuthLoginViewModel.kt

@@ -8,6 +8,7 @@ import androidx.lifecycle.viewModelScope
 import com.m57.hermescontrol.R
 import com.m57.hermescontrol.data.config.ConnectionProfile
 import com.m57.hermescontrol.data.local.AuthManager
+import com.m57.hermescontrol.data.local.AuthSessionState
 import com.m57.hermescontrol.data.remote.ApiClient
 import com.m57.hermescontrol.data.remote.AuthPayloads
 import com.m57.hermescontrol.data.remote.CleartextPolicy
@@ -80,9 +81,20 @@ class AuthLoginViewModel(
 
     init {
         loadLoggedInProfiles()
+        viewModelScope.launch {
+            AuthSessionState.signInRequired.collect { required ->
+                if (required) {
+                    _uiState.update { it.copy(loggedInProfiles = emptyList()) }
+                }
+            }
+        }
     }
 
     fun loadLoggedInProfiles() {
+        if (AuthSessionState.signInRequired.value) {
+            _uiState.update { it.copy(loggedInProfiles = emptyList()) }
+            return
+        }
         val allProfiles = AuthManager.getConnectionProfiles()
         val loggedIn =
             allProfiles.filter { profile ->
@@ -95,6 +107,7 @@ class AuthLoginViewModel(
     fun useExistingProfile(profileId: String) {
         AuthManager.setSelectedProfileId(profileId)
         ApiClient.rebuild()
+        AuthSessionState.markAuthenticated()
         HermesWsClient.connect()
         _uiState.update { it.copy(connectionSuccess = true) }
     }
@@ -345,6 +358,7 @@ class AuthLoginViewModel(
                     AuthManager.setWsAuthParam("ticket")
                 }
                 ApiClient.rebuild()
+                AuthSessionState.markAuthenticated()
                 HermesWsClient.connect()
                 _uiState.update { it.copy(isLoading = false, connectionSuccess = true) }
             }
@@ -366,7 +380,7 @@ class AuthLoginViewModel(
         }
 
         val tempApi = ApiClient.createTempService(endpoint.baseUrl.toString(), token)
-        val result = safeApiCall { tempApi.getSessions() }
+        val result = safeApiCall(reportAuthExpiry = false) { tempApi.getSessions() }
 
         return when (result) {
             is com.m57.hermescontrol.data.remote.NetworkResult.Success -> {

app/src/main/java/com/m57/hermescontrol/ui/chat/ChatViewModel.kt

@@ -8,6 +8,7 @@ import android.util.Log
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.viewModelScope
 import com.m57.hermescontrol.data.local.AuthManager
+import com.m57.hermescontrol.data.local.AuthSessionState
 import com.m57.hermescontrol.data.local.HermesDatabase
 import com.m57.hermescontrol.data.model.Attachment
 import com.m57.hermescontrol.data.model.ModelProvider
@@ -1854,6 +1855,7 @@ class ChatViewModel(
     }
 
     fun reconnect() {
+        AuthSessionState.markAuthenticated()
         _uiState.update {
             it.copy(
                 isLoading = true,
@@ -1951,6 +1953,7 @@ class ChatViewModel(
 
                     AuthManager.setWsAuthParam("ticket")
                     AuthManager.setToken(ticket)
+                    AuthSessionState.markAuthenticated()
 
                     withContext(Dispatchers.Main) {
                         onResult(true, null)

app/src/main/java/com/m57/hermescontrol/ui/connect/ConnectViewModel.kt

@@ -8,6 +8,7 @@ import com.m57.hermescontrol.R
 import com.m57.hermescontrol.data.config.ConnectionProfile
 import com.m57.hermescontrol.data.config.resolveBaseUrl
 import com.m57.hermescontrol.data.local.AuthManager
+import com.m57.hermescontrol.data.local.AuthSessionState
 import com.m57.hermescontrol.data.remote.ApiClient
 import com.m57.hermescontrol.data.remote.CleartextPolicy
 import com.m57.hermescontrol.data.remote.NetworkError
@@ -115,7 +116,7 @@ class ConnectViewModel(
             val result =
                 withContext(Dispatchers.IO) {
                     val tempApi = ApiClient.createTempService(endpoint.baseUrl.toString(), state.token)
-                    safeApiCall { tempApi.getStatus() }
+                    safeApiCall(reportAuthExpiry = false) { tempApi.getStatus() }
                 }
             when (result) {
                 is NetworkResult.Success -> {
@@ -123,6 +124,7 @@ class ConnectViewModel(
                     AuthManager.setToken(state.token)
                     AuthManager.setBaseUrl(state.baseUrl)
                     ApiClient.rebuild()
+                    AuthSessionState.markAuthenticated()
 
                     if (state.saveProfile) {
                         val currentProfiles = AuthManager.getConnectionProfiles()