feat(chat): handle sudo.request / secret.request and respond via RPC (fixes #524) (#539)

Previously mobile dropped the gateway's sudo.request and secret.request
events, so any agent turn needing a sudo password or a secret value hung
forever with no UI. Now:
- EventParser maps sudo.request / secret.request -> WsEvent.SudoRequest / SecretRequest
- ChatViewModel surfaces a secure dialog (SudoPromptUi / SecretPromptUi) and
  replies via sudo.respond / secret.respond with session_id + request_id + payload
- ChatWsEventReducer explicitly branches the new events (no-op, VM-owned)
- ChatScreen renders password-masked SudoPromptDialog / SecretPromptDialog
- 6 unit tests cover prompt-state, RPC params, and prompt-clearing

Mirrors desktop/web contract (apps/shared GatewayEventName + tui_gateway).
Derives from audit of /opt/hermes-agent desktop app.

app/src/main/java/com/m57/hermescontrol/data/ws/EventParser.kt

@@ -115,6 +115,16 @@ object EventParser {
                 WsEvent.ApprovalRequest(command, description, patternKeys, sessionId)
             }
 
+            "sudo.request" -> {
+                val requestId = payload?.get("request_id") as? String
+                WsEvent.SudoRequest(requestId, sessionId)
+            }
+
+            "secret.request" -> {
+                val requestId = payload?.get("request_id") as? String
+                WsEvent.SecretRequest(requestId, sessionId)
+            }
+
             else -> {
                 Log.w(TAG, "Unknown event type: $eventType")
                 WsEvent.Unknown(rawJson)

app/src/main/java/com/m57/hermescontrol/data/ws/WsEvent.kt

@@ -94,6 +94,28 @@ sealed class WsEvent {
         val sessionId: String?,
     ) : WsEvent()
 
+    // ── Sudo / secret requests ─────────────────────────────────────────
+
+    /**
+     * Backend needs the user's sudo password to continue a turn
+     * (desktop: `sudo.request` → `sudo.respond {request_id, password}`).
+     * Mobile previously dropped this and the agent hung forever.
+     */
+    data class SudoRequest(
+        val requestId: String?,
+        val sessionId: String?,
+    ) : WsEvent()
+
+    /**
+     * Backend needs a secret value (password / token) to continue a turn
+     * (desktop: `secret.request` → `secret.respond {request_id, value}`).
+     * Mobile previously dropped this and the agent hung forever.
+     */
+    data class SecretRequest(
+        val requestId: String?,
+        val sessionId: String?,
+    ) : WsEvent()
+
     // ── Fallback ─────────────────────────────────────────────────────────
 
     data class Unknown(

app/src/main/java/com/m57/hermescontrol/data/ws/WsMethods.kt

@@ -17,6 +17,8 @@ object WsMethods {
     const val PROMPT_SUBMIT = "prompt.submit"
     const val CLARIFY_RESPOND = "clarify.respond"
     const val APPROVAL_RESPOND = "approval.respond"
+    const val SUDO_RESPOND = "sudo.respond"
+    const val SECRET_RESPOND = "secret.respond"
 
     // ── Commands catalog ──────────────────────────────────────────────────
     const val COMMANDS_CATALOG = "commands.catalog"

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

@@ -101,6 +101,8 @@ import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.Role
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.input.PasswordVisualTransformation
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
@@ -275,6 +277,8 @@ fun ChatScreen(
         currentSearchMatchIndex = state.currentSearchMatchIndex,
         searchMatchIndices = state.searchMatchIndices,
         clarifyRequest = state.clarifyRequest,
+        sudoPrompt = state.sudoPrompt,
+        secretPrompt = state.secretPrompt,
         listState = listState,
         snackbarHostState = snackbarHostState,
         viewModel = viewModel,
@@ -1004,6 +1008,106 @@ private fun ClarifyDialog(
     )
 }
 
+/**
+ * Secure password dialog for a pending `sudo.request` (issue #524).
+ * The backend blocked the turn waiting for the sudo password — previously
+ * mobile dropped the event and the agent hung forever.
+ */
+@Composable
+private fun SudoPromptDialog(
+    onConfirm: (String) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    var password by remember { mutableStateOf("") }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text(stringResource(R.string.chat_sudo_title)) },
+        text = {
+            Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                Text(text = stringResource(R.string.chat_sudo_body))
+                Spacer(modifier = Modifier.height(4.dp))
+                OutlinedTextField(
+                    value = password,
+                    onValueChange = { password = it },
+                    label = { Text(stringResource(R.string.chat_sudo_password)) },
+                    modifier = Modifier.fillMaxWidth().testTag("sudo_password_input"),
+                    singleLine = true,
+                    visualTransformation = PasswordVisualTransformation(),
+                    keyboardOptions = KeyboardOptions(autoCorrect = false, keyboardType = KeyboardType.Password),
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(
+                onClick = {
+                    if (password.isNotBlank()) {
+                        onConfirm(password)
+                    }
+                },
+                enabled = password.isNotBlank(),
+            ) {
+                Text(stringResource(R.string.chat_send))
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) {
+                Text(stringResource(R.string.chat_dismiss))
+            }
+        },
+    )
+}
+
+/**
+ * Secure value dialog for a pending `secret.request` (issue #524).
+ * The backend blocked the turn waiting for a secret (token/password) —
+ * previously mobile dropped the event and the agent hung forever.
+ */
+@Composable
+private fun SecretPromptDialog(
+    onConfirm: (String) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    var secret by remember { mutableStateOf("") }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text(stringResource(R.string.chat_secret_title)) },
+        text = {
+            Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                Text(text = stringResource(R.string.chat_secret_body))
+                Spacer(modifier = Modifier.height(4.dp))
+                OutlinedTextField(
+                    value = secret,
+                    onValueChange = { secret = it },
+                    label = { Text(stringResource(R.string.chat_secret_value)) },
+                    modifier = Modifier.fillMaxWidth().testTag("secret_value_input"),
+                    singleLine = true,
+                    visualTransformation = PasswordVisualTransformation(),
+                    keyboardOptions = KeyboardOptions(autoCorrect = false, keyboardType = KeyboardType.Password),
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(
+                onClick = {
+                    if (secret.isNotBlank()) {
+                        onConfirm(secret)
+                    }
+                },
+                enabled = secret.isNotBlank(),
+            ) {
+                Text(stringResource(R.string.chat_send))
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) {
+                Text(stringResource(R.string.chat_dismiss))
+            }
+        },
+    )
+}
+
 @Composable
 private fun CompactSearchInput(
     value: String,
@@ -1230,6 +1334,8 @@ private fun ChatLifecycleEffects(
     currentSearchMatchIndex: Int,
     searchMatchIndices: List<Int>,
     clarifyRequest: ClarifyUi?,
+    sudoPrompt: SudoPromptUi?,
+    secretPrompt: SecretPromptUi?,
     listState: LazyListState,
     snackbarHostState: SnackbarHostState,
     viewModel: ChatViewModel,
@@ -1330,6 +1436,21 @@ private fun ChatLifecycleEffects(
         )
     }
 
+    // Sudo / secret prompt dialogs (issue #524)
+    sudoPrompt?.let { prompt ->
+        SudoPromptDialog(
+            onConfirm = viewModel::respondToSudo,
+            onDismiss = viewModel::dismissSudo,
+        )
+    }
+
+    secretPrompt?.let { prompt ->
+        SecretPromptDialog(
+            onConfirm = viewModel::respondToSecret,
+            onDismiss = viewModel::dismissSecret,
+        )
+    }
+
     // Scroll to current search match
     LaunchedEffect(isSearchActive, currentSearchMatchIndex, searchMatchIndices) {
         if (isSearchActive &&

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

@@ -70,6 +70,9 @@ data class ChatUiState(
     val streamingMessage: ChatMessage? = null,
     val errorMessage: String? = null,
     val clarifyRequest: ClarifyUi? = null,
+    // Sudo / secret prompts — surfaced as dialogs (issue #524)
+    val sudoPrompt: SudoPromptUi? = null,
+    val secretPrompt: SecretPromptUi? = null,
     val showSessionPicker: Boolean = false,
     // Search state
     val isSearchActive: Boolean = false,
@@ -100,6 +103,18 @@ data class ClarifyUi(
     val clarifyId: String? = null,
 )
 
+/** Transient — not persisted. Holds a pending sudo.password request. */
+data class SudoPromptUi(
+    val requestId: String?,
+    val sessionId: String?,
+)
+
+/** Transient — not persisted. Holds a pending secret (token/password) request. */
+data class SecretPromptUi(
+    val requestId: String?,
+    val sessionId: String?,
+)
+
 class ChatViewModel(
     application: Application,
     private val startCleanup: Boolean,
@@ -358,6 +373,14 @@ class ChatViewModel(
                 handleApprovalRequest(event)
             }
 
+            is WsEvent.SudoRequest -> {
+                handleSudoRequest(event)
+            }
+
+            is WsEvent.SecretRequest -> {
+                handleSecretRequest(event)
+            }
+
             else -> { /* reducer handles these */ }
         }
     }
@@ -1096,6 +1119,94 @@ class ChatViewModel(
         }
     }
 
+    // ── Sudo / secret prompt flow (issue #524) ──────────────────────────
+
+    /**
+     * The agent needs the user's sudo password. Previously dropped → agent
+     * hung forever. Now we surface a secure dialog and reply via sudo.respond.
+     */
+    private fun handleSudoRequest(event: WsEvent.SudoRequest) {
+        _uiState.update {
+            it.copy(
+                sudoPrompt = SudoPromptUi(event.requestId, event.sessionId),
+                isAgentTyping = false,
+            )
+        }
+    }
+
+    /**
+     * The agent needs a secret value (token/password). Previously dropped →
+     * agent hung forever. Now we surface a secure dialog and reply via
+     * secret.respond.
+     */
+    private fun handleSecretRequest(event: WsEvent.SecretRequest) {
+        _uiState.update {
+            it.copy(
+                secretPrompt = SecretPromptUi(event.requestId, event.sessionId),
+                isAgentTyping = false,
+            )
+        }
+    }
+
+    fun dismissSudo() {
+        _uiState.update { it.copy(sudoPrompt = null) }
+    }
+
+    fun dismissSecret() {
+        _uiState.update { it.copy(secretPrompt = null) }
+    }
+
+    /**
+     * Send the user's sudo password back to the gateway. Mirrors
+     * respondToApproval: clear the prompt immediately, then fire the RPC.
+     */
+    fun respondToSudo(password: String) {
+        val prompt = _uiState.value.sudoPrompt ?: return
+        val sessionId = prompt.sessionId ?: _uiState.value.currentSessionId ?: return
+        if (password.isBlank()) return
+
+        _uiState.update { it.copy(sudoPrompt = null) }
+
+        viewModelScope.launch(Dispatchers.IO) {
+            val params =
+                mutableMapOf<String, Any>(
+                    "session_id" to sessionId,
+                    "password" to password,
+                )
+            prompt.requestId?.let { id -> params["request_id"] = id }
+            wsClient.send(
+                method = WsMethods.SUDO_RESPOND,
+                params = params,
+                onSent = { id -> trackRequest(id, WsMethods.SUDO_RESPOND) },
+            )
+        }
+    }
+
+    /**
+     * Send the user's secret value back to the gateway. Mirrors respondToSudo.
+     */
+    fun respondToSecret(value: String) {
+        val prompt = _uiState.value.secretPrompt ?: return
+        val sessionId = prompt.sessionId ?: _uiState.value.currentSessionId ?: return
+        if (value.isBlank()) return
+
+        _uiState.update { it.copy(secretPrompt = null) }
+
+        viewModelScope.launch(Dispatchers.IO) {
+            val params =
+                mutableMapOf<String, Any>(
+                    "session_id" to sessionId,
+                    "value" to value,
+                )
+            prompt.requestId?.let { id -> params["request_id"] = id }
+            wsClient.send(
+                method = WsMethods.SECRET_RESPOND,
+                params = params,
+                onSent = { id -> trackRequest(id, WsMethods.SECRET_RESPOND) },
+            )
+        }
+    }
+
     fun reconnect() {
         _uiState.update {
             it.copy(

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

@@ -80,6 +80,10 @@ object ChatWsEventReducer {
 
             // ApprovalRequest is handled by the ViewModel (needs active session + WS client)
             is WsEvent.ApprovalRequest -> ReducerResult(state = state, streamingState = streamingState)
+
+            // SudoRequest / SecretRequest are handled by the ViewModel (issue #524)
+            is WsEvent.SudoRequest -> ReducerResult(state = state, streamingState = streamingState)
+            is WsEvent.SecretRequest -> ReducerResult(state = state, streamingState = streamingState)
         }
 
     // ── GatewayReady ──────────────────────────────────────────────────