feat(relayauth): user toggle for trusting follows' outboxes on reads

Add relayAuthTrustFollowsForReads (local AccountSettings flag, persisted
via LocalPreferences, default off) and wire it into the ledger's
readTrustEnabled input. The relay-auth settings screen shows a switch —
"Also trust when reading their posts" — under the Trusted-follows policy,
so downloading a followed author's outbox auto-authenticates only when
the user opts in; writes (DMs/notifications) remain auto-trusted.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EZjmYpgHP4pf79Sav5QT8a

amethyst/src/main/java/com/vitorpamplona/amethyst/LocalPreferences.kt

@@ -162,6 +162,7 @@ private object PrefKeys {
     const val ALWAYS_ON_NOTIFICATION_SERVICE = "always_on_notification_service"
     const val DEFAULT_RELAY_AUTH_POLICY = "default_relay_auth_policy"
     const val RELAY_GROUP_VIEW_MODE = "relay_group_view_mode"
+    const val RELAY_AUTH_TRUST_FOLLOWS_FOR_READS = "relay_auth_trust_follows_for_reads"
     const val SPLIT_NOTIFICATIONS_ENABLED = "split_notifications_enabled"
     const val SHOW_MESSAGES_IN_NOTIFICATIONS = "show_messages_in_notifications"
 
@@ -517,6 +518,7 @@ object LocalPreferences {
                     putBoolean(PrefKeys.ALWAYS_ON_NOTIFICATION_SERVICE, settings.alwaysOnNotificationService.value)
                     putString(PrefKeys.DEFAULT_RELAY_AUTH_POLICY, settings.defaultRelayAuthPolicy.value.name)
                     putString(PrefKeys.RELAY_GROUP_VIEW_MODE, settings.relayGroupViewMode.value.name)
+                    putBoolean(PrefKeys.RELAY_AUTH_TRUST_FOLLOWS_FOR_READS, settings.relayAuthTrustFollowsForReads.value)
                     putBoolean(PrefKeys.SPLIT_NOTIFICATIONS_ENABLED, settings.splitNotificationsEnabled.value)
                     putBoolean(PrefKeys.SHOW_MESSAGES_IN_NOTIFICATIONS, settings.showMessagesInNotifications.value)
                     // Any account that reaches a save has its notification filter in its
@@ -638,6 +640,7 @@ object LocalPreferences {
                             ?.let { runCatching { RelayAuthPolicy.valueOf(it) }.getOrNull() }
                             ?: RelayAuthPolicy.IF_IN_MY_LIST
                     val relayGroupViewMode = RelayGroupViewMode.fromName(getString(PrefKeys.RELAY_GROUP_VIEW_MODE, null))
+                    val relayAuthTrustFollowsForReads = getBoolean(PrefKeys.RELAY_AUTH_TRUST_FOLLOWS_FOR_READS, false)
                     val splitNotificationsEnabled = getBoolean(PrefKeys.SPLIT_NOTIFICATIONS_ENABLED, false)
                     val showMessagesInNotifications = getBoolean(PrefKeys.SHOW_MESSAGES_IN_NOTIFICATIONS, true)
                     val hasDonatedInVersion = getStringSet(PrefKeys.HAS_DONATED_IN_VERSION, null) ?: setOf()
@@ -847,6 +850,7 @@ object LocalPreferences {
                         alwaysOnNotificationService = MutableStateFlow(alwaysOnNotificationService),
                         defaultRelayAuthPolicy = MutableStateFlow(defaultRelayAuthPolicy),
                         relayGroupViewMode = MutableStateFlow(relayGroupViewMode),
+                        relayAuthTrustFollowsForReads = MutableStateFlow(relayAuthTrustFollowsForReads),
                         splitNotificationsEnabled = MutableStateFlow(splitNotificationsEnabled),
                         showMessagesInNotifications = MutableStateFlow(showMessagesInNotifications),
                         backupUserMetadata = latestUserMetadataResolved,

amethyst/src/main/java/com/vitorpamplona/amethyst/model/AccountSettings.kt

@@ -275,6 +275,7 @@ class AccountSettings(
     val callsEnabled: MutableStateFlow<Boolean> = MutableStateFlow(true),
     val defaultRelayAuthPolicy: MutableStateFlow<RelayAuthPolicy> = MutableStateFlow(RelayAuthPolicy.IF_IN_MY_LIST),
     val relayGroupViewMode: MutableStateFlow<RelayGroupViewMode> = MutableStateFlow(RelayGroupViewMode.DEFAULT),
+    val relayAuthTrustFollowsForReads: MutableStateFlow<Boolean> = MutableStateFlow(false),
 ) : EphemeralChatRepository,
     RelayGroupRepository,
     PublicChatListRepository {
@@ -1524,6 +1525,13 @@ class AccountSettings(
             saveAccountSettings()
         }
     }
+
+    fun changeRelayAuthTrustFollowsForReads(enabled: Boolean) {
+        if (relayAuthTrustFollowsForReads.value != enabled) {
+            relayAuthTrustFollowsForReads.tryEmit(enabled)
+            saveAccountSettings()
+        }
+    }
 }
 
 @Serializable

amethyst/src/main/java/com/vitorpamplona/amethyst/service/relayClient/authCommand/compose/AccountDataSourceSubscription.kt

@@ -61,6 +61,7 @@ fun RelayAuthSubscription(
                 // Any follow list (kind 3, follow sets, etc.) counts as trusting the counterparty
                 // enough to reveal our identity to a relay that serves them.
                 isFollowed = { pubkey -> pubkey in account.allFollows.flow.value.authors },
+                readTrustEnabled = { account.settings.relayAuthTrustFollowsForReads.value },
             )
         }
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/relayauth/RelayAuthSettingsScreen.kt

@@ -38,6 +38,7 @@ import androidx.compose.material3.Scaffold
 import androidx.compose.material3.SuggestionChip
 import androidx.compose.material3.SuggestionChipDefaults
 import androidx.compose.material3.Surface
+import androidx.compose.material3.Switch
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
@@ -154,6 +155,30 @@ fun RelayAuthSettingsScreen(
                 }
             }
 
+            if (globalPolicy == RelayAuthPolicy.TRUSTED_FOLLOWS) {
+                val trustReads by account.settings.relayAuthTrustFollowsForReads.collectAsState()
+                Row(
+                    modifier = Modifier.fillMaxWidth().padding(top = 8.dp),
+                    verticalAlignment = Alignment.CenterVertically,
+                ) {
+                    Column(modifier = Modifier.weight(1f)) {
+                        Text(
+                            text = stringResource(R.string.relay_auth_trust_reads),
+                            style = MaterialTheme.typography.bodyLarge,
+                        )
+                        Text(
+                            text = stringResource(R.string.relay_auth_trust_reads_desc),
+                            style = MaterialTheme.typography.bodyMedium,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        )
+                    }
+                    Switch(
+                        checked = trustReads,
+                        onCheckedChange = { account.settings.changeRelayAuthTrustFollowsForReads(it) },
+                    )
+                }
+            }
+
             Spacer(Modifier.height(8.dp))
             HorizontalDivider()
             Spacer(Modifier.height(8.dp))

amethyst/src/main/res/values/strings.xml

@@ -827,6 +827,8 @@
     <string name="relay_auth_policy_if_in_my_list_desc">Only authenticate with relays in your relay list</string>
     <string name="relay_auth_policy_trusted_follows">My relays and people I follow</string>
     <string name="relay_auth_policy_trusted_follows_desc">Also authenticate with relays that serve people you follow, such as sending a message to a friend. You\'ll be asked about anyone else.</string>
+    <string name="relay_auth_trust_reads">Also trust when reading their posts</string>
+    <string name="relay_auth_trust_reads_desc">Log in automatically to download posts from people you follow, not just to message or notify them.</string>
     <string name="relay_auth_prompt_title">Log in to this relay?</string>
     <string name="relay_auth_prompt_message">This relay asks you to log in before it will:</string>
     <string name="relay_auth_reason_send_dm">Send your private message to:</string>