feat: surface /api/status memory+disk pressure on connect/status screens (#903) (#908)

Co-authored-by: M57 <hy4ri@users.noreply.github.com>

app/src/main/java/com/m57/hermescontrol/ui/common/PressureBanner.kt

@@ -0,0 +1,133 @@
+package com.m57.hermescontrol.ui.common
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Warning
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import com.m57.hermescontrol.R
+import com.m57.hermescontrol.data.model.DiskPressureStatus
+import com.m57.hermescontrol.data.model.MemoryPressureStatus
+import com.m57.hermescontrol.theme.LocalHermesStatusColors
+import com.m57.hermescontrol.theme.onColorFor
+
+/**
+ * Worst-first severity of the host-health advisory (mirrors the desktop
+ * `MemoryPressureBanner` trigger order, issue #903): disk critical beats
+ * memory critical (imminent data loss beats imminent restart), and a
+ * suspected-OOM restart is a post-mortem that beats plain elevated states.
+ */
+enum class PressureTrigger {
+    DISK_CRITICAL,
+    MEMORY_CRITICAL,
+    OOM_RESTART,
+    DISK_ELEVATED,
+    MEMORY_ELEVATED,
+}
+
+/**
+ * Picks the advisory to surface from the `/api/status` memory/disk blocks.
+ * Returns `null` when there is nothing to warn about. `unknown` pressure is
+ * absence of evidence, not recovery — it never triggers (and never clears)
+ * a banner, same as the desktop banner.
+ */
+internal fun selectPressureTrigger(
+    memory: MemoryPressureStatus?,
+    disk: DiskPressureStatus?,
+): PressureTrigger? =
+    when {
+        disk?.pressure == "critical" -> PressureTrigger.DISK_CRITICAL
+        memory?.pressure == "critical" -> PressureTrigger.MEMORY_CRITICAL
+        memory?.last_boot_suspected_oom == true -> PressureTrigger.OOM_RESTART
+        disk?.pressure == "elevated" -> PressureTrigger.DISK_ELEVATED
+        memory?.pressure == "elevated" -> PressureTrigger.MEMORY_ELEVATED
+        else -> null
+    }
+
+/**
+ * Small advisory banner for host resource trouble (issue #903): renders when
+ * the backend's `/api/status` reports memory/disk pressure, so an OOM-thrashing
+ * or disk-full host explains itself instead of looking like a dead agent.
+ * Advisory only — it never gates anything and never blocks the UI.
+ */
+@Composable
+fun PressureBanner(
+    memory: MemoryPressureStatus?,
+    disk: DiskPressureStatus?,
+    modifier: Modifier = Modifier,
+) {
+    val trigger = selectPressureTrigger(memory, disk) ?: return
+    val statusColors = LocalHermesStatusColors.current
+    val critical =
+        trigger == PressureTrigger.DISK_CRITICAL ||
+            trigger == PressureTrigger.MEMORY_CRITICAL
+    val bgColor =
+        if (critical) {
+            statusColors.errorContainer
+        } else {
+            statusColors.warningContainer
+        }
+    val fgColor = onColorFor(bgColor)
+
+    val message =
+        when (trigger) {
+            PressureTrigger.DISK_CRITICAL ->
+                stringResource(R.string.pressure_banner_disk_critical) +
+                    diskFreeSuffix(disk)
+
+            PressureTrigger.DISK_ELEVATED ->
+                stringResource(R.string.pressure_banner_disk_elevated) +
+                    diskFreeSuffix(disk)
+
+            PressureTrigger.MEMORY_CRITICAL ->
+                stringResource(R.string.pressure_banner_memory_critical)
+
+            PressureTrigger.OOM_RESTART ->
+                stringResource(R.string.pressure_banner_memory_oom)
+
+            PressureTrigger.MEMORY_ELEVATED ->
+                stringResource(R.string.pressure_banner_memory_elevated)
+        }
+
+    Surface(
+        modifier = modifier.fillMaxWidth(),
+        shape = MaterialTheme.shapes.medium,
+        color = bgColor,
+    ) {
+        Row(
+            modifier = Modifier.padding(horizontal = 12.dp, vertical = 8.dp),
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+        ) {
+            Icon(
+                imageVector = Icons.Filled.Warning,
+                contentDescription = null,
+                tint = fgColor,
+                modifier = Modifier.size(16.dp),
+            )
+            Text(
+                text = message,
+                style = MaterialTheme.typography.bodySmall,
+                color = fgColor,
+                modifier = Modifier.weight(1f),
+            )
+        }
+    }
+}
+
+@Composable
+private fun diskFreeSuffix(disk: DiskPressureStatus?): String {
+    val freeMb = disk?.free_mb ?: return ""
+    return stringResource(R.string.pressure_banner_disk_free_suffix, freeMb)
+}

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

@@ -58,6 +58,7 @@ import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
 import com.m57.hermescontrol.R
+import com.m57.hermescontrol.ui.common.PressureBanner
 
 @Composable
 fun ConnectScreen(
@@ -354,6 +355,12 @@ fun ConnectScreen(
                         }
                     }
                 }
+                // Host-health advisory (issue #903): memory/disk pressure from
+                // the /api/status probe — explains a struggling host before or
+                // after a failed connect attempt.
+                state.status?.let { status ->
+                    PressureBanner(memory = status.memory, disk = status.disk)
+                }
             }
         }
     }

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

@@ -9,6 +9,7 @@ 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.model.HealthStatus
+import com.m57.hermescontrol.data.model.StatusResponse
 import com.m57.hermescontrol.data.remote.ApiClient
 import com.m57.hermescontrol.data.remote.CleartextPolicy
 import com.m57.hermescontrol.data.remote.NetworkError
@@ -33,6 +34,7 @@ data class ConnectUiState(
     val profiles: List<ConnectionProfile> = emptyList(),
     val selectedProfile: ConnectionProfile? = null,
     val health: HealthStatus? = null,
+    val status: StatusResponse? = null,
 )
 
 class ConnectViewModel(
@@ -61,6 +63,7 @@ class ConnectViewModel(
             )
         }
         loadHealth()
+        loadStatus()
     }
 
     /**
@@ -84,6 +87,28 @@ class ConnectViewModel(
         }
     }
 
+    /**
+     * Best-effort `/api/status` probe (issue #903): surfaces the host
+     * memory/disk pressure banner on the connection screen. Fired on screen
+     * load (saved credentials) and after a failed connect, so an OOM-thrashing
+     * or disk-full host explains itself instead of looking like a dead agent.
+     * Failures are silent (status stays null and the screen shows no banner).
+     */
+    fun loadStatus() {
+        val state = _uiState.value
+        val endpoint = runCatching { ServerEndpoint.parseForBuild(state.baseUrl) }.getOrNull()
+        if (endpoint == null || state.token.isBlank()) return
+        viewModelScope.launch {
+            val result =
+                safeApiCall {
+                    ApiClient.createTempService(endpoint.baseUrl.toString(), state.token).getStatus()
+                }
+            if (result is NetworkResult.Success) {
+                _uiState.update { it.copy(status = result.data) }
+            }
+        }
+    }
+
     fun onProfileNameChange(value: String) {
         _uiState.update { it.copy(profileName = value, errorMessage = null) }
     }
@@ -180,7 +205,12 @@ class ConnectViewModel(
                     }
                     ApiClient.rebuild()
                     _uiState.update {
-                        it.copy(isConnecting = false, connectionSuccess = true, errorMessage = null)
+                        it.copy(
+                            isConnecting = false,
+                            connectionSuccess = true,
+                            errorMessage = null,
+                            status = result.data,
+                        )
                     }
                 }
 
@@ -282,6 +312,8 @@ class ConnectViewModel(
                             }
                         }
                     _uiState.update { it.copy(isConnecting = false, errorMessage = msg) }
+                    // Best-effort: explain a failing host via its pressure rollup.
+                    loadStatus()
                 }
             }
         }

app/src/main/java/com/m57/hermescontrol/ui/gateway/GatewayScreen.kt

@@ -39,6 +39,7 @@ import com.m57.hermescontrol.theme.LocalHermesStatusColors
 import com.m57.hermescontrol.ui.common.ErrorState
 import com.m57.hermescontrol.ui.common.HermesScaffold
 import com.m57.hermescontrol.ui.common.NavIcon
+import com.m57.hermescontrol.ui.common.PressureBanner
 import com.m57.hermescontrol.ui.common.SkeletonListState
 import com.m57.hermescontrol.ui.common.ToastEffect
 
@@ -108,6 +109,11 @@ fun GatewayScreen(
                         ) {
                             val isRunning = status?.gateway_running == true
 
+                            // Host-health advisory (issue #903): memory/disk pressure
+                            status?.let { s ->
+                                PressureBanner(memory = s.memory, disk = s.disk)
+                            }
+
                             // Status Overview Card
                             Card(
                                 modifier = Modifier.fillMaxWidth(),