feat: add connection status indicator (Issue #28)

Adds a colored dot next to the '⚡ Hermes' brand header in the
navigation drawer:
  - Green: connected
  - Yellow: connecting / reconnecting
  - Red: disconnected

Uses a StateFlow on HermesWsClient that tracks the WebSocket
connection lifecycle and is collected in the drawer header.

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

@@ -1,5 +1,8 @@
 package com.m57.hermescontrol
 
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.WindowInsets
 import androidx.compose.foundation.layout.fillMaxSize
@@ -7,7 +10,10 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.navigationBars
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.safeDrawingPadding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.Chat
@@ -39,12 +45,15 @@ import androidx.compose.material3.NavigationDrawerItemDefaults
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 import androidx.compose.material3.rememberDrawerState
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
@@ -53,6 +62,8 @@ import androidx.navigation3.runtime.entryProvider
 import androidx.navigation3.runtime.rememberNavBackStack
 import androidx.navigation3.ui.NavDisplay
 import com.m57.hermescontrol.data.local.AuthManager
+import com.m57.hermescontrol.data.ws.ConnectionStatus
+import com.m57.hermescontrol.data.ws.HermesWsClient
 import kotlinx.coroutines.launch
 import com.m57.hermescontrol.ui.achievements.AchievementsScreen as AchievementsScreenContent
 import com.m57.hermescontrol.ui.channels.ChannelsScreen as ChannelsScreenContent
@@ -188,16 +199,34 @@ fun MainNavigation() {
                 ModalDrawerSheet(
                     modifier = Modifier.verticalScroll(rememberScrollState()),
                 ) {
-                    // Brand header
-                    Text(
-                        text = "⚡ Hermes",
+                    // Brand header with connection status
+                    val connectionStatus by HermesWsClient.connectionStatus.collectAsState()
+                    val statusColor = when (connectionStatus) {
+                        ConnectionStatus.CONNECTED -> Color(0xFF4CAF50)    // green
+                        ConnectionStatus.CONNECTING,
+                        ConnectionStatus.RECONNECTING -> Color(0xFFFFC107) // yellow
+                        ConnectionStatus.DISCONNECTED -> Color(0xFFF44336) // red
+                    }
+                    Row(
+                        verticalAlignment = Alignment.CenterVertically,
                         modifier = Modifier.padding(start = 20.dp, top = 20.dp, end = 16.dp, bottom = 4.dp),
-                        style =
-                            MaterialTheme.typography.headlineSmall.copy(
-                                fontWeight = FontWeight.Bold,
-                            ),
-                        color = MaterialTheme.colorScheme.primary,
-                    )
+                    ) {
+                        Text(
+                            text = "⚡ Hermes",
+                            style =
+                                MaterialTheme.typography.headlineSmall.copy(
+                                    fontWeight = FontWeight.Bold,
+                                ),
+                            color = MaterialTheme.colorScheme.primary,
+                        )
+                        Spacer(modifier = Modifier.width(8.dp))
+                        Box(
+                            modifier =
+                                Modifier
+                                    .size(10.dp)
+                                    .background(color = statusColor, shape = CircleShape),
+                        )
+                    }
                     Text(
                         text = "AI Agent Control",
                         modifier = Modifier.padding(start = 20.dp, bottom = 12.dp, end = 16.dp),

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

@@ -10,8 +10,11 @@ import kotlinx.coroutines.Job
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asSharedFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.launch
 import okhttp3.OkHttpClient
 import okhttp3.Request
@@ -22,6 +25,16 @@ import java.util.concurrent.TimeUnit
 import java.util.concurrent.atomic.AtomicBoolean
 import java.util.concurrent.atomic.AtomicInteger
 
+/**
+ * Connection status for the WebSocket client.
+ */
+enum class ConnectionStatus {
+    DISCONNECTED,
+    CONNECTING,
+    CONNECTED,
+    RECONNECTING,
+}
+
 /**
  * WebSocket client for the Hermes Dashboard JSON-RPC 2.0 interface.
  *
@@ -74,6 +87,12 @@ object HermesWsClient {
     /** Collect this from ViewModels to receive all parsed [WsEvent]s. */
     val events: SharedFlow<WsEvent> = _events.asSharedFlow()
 
+    // ── Connection status flow ──────────────────────────────────────────
+    private val _connectionStatus = MutableStateFlow(ConnectionStatus.DISCONNECTED)
+
+    /** Observable connection status: DISCONNECTED / CONNECTING / CONNECTED / RECONNECTING */
+    val connectionStatus: StateFlow<ConnectionStatus> = _connectionStatus.asStateFlow()
+
     // ── Callbacks (legacy / convenience) ─────────────────────────────────
 
     var onMessage: ((WsEvent) -> Unit)? = null
@@ -93,20 +112,19 @@ object HermesWsClient {
         }
         intentionalClose.set(false)
         currentBackoff = INITIAL_BACKOFF_MS
+        _connectionStatus.value = ConnectionStatus.CONNECTING
         openSocket()
     }
 
     /** Cleanly close the WebSocket and stop auto-reconnect. */
     fun disconnect() {
         intentionalClose.set(true)
-        // B4 (Jun 18 2026, kanban t_2b834d90): also cancel any pending
-        // reconnect coroutine so a scheduled openSocket() can't fire after
-        // the user explicitly disconnected.
         reconnectJob?.cancel()
         reconnectJob = null
         webSocket?.close(1000, "Client closed")
         webSocket = null
         connected.set(false)
+        _connectionStatus.value = ConnectionStatus.DISCONNECTED
     }
 
     // ── Send helpers ─────────────────────────────────────────────────────
@@ -156,6 +174,7 @@ object HermesWsClient {
         if (intentionalClose.get()) return
         if (!AuthManager.isAutoReconnect()) {
             if (BuildConfig.DEBUG) Log.d(TAG, "Auto-reconnect disabled")
+            _connectionStatus.value = ConnectionStatus.DISCONNECTED
             return
         }
         val delay = currentBackoff
@@ -205,6 +224,7 @@ object HermesWsClient {
         ) {
             Log.i(TAG, "WebSocket opened")
             connected.set(true)
+            _connectionStatus.value = ConnectionStatus.CONNECTED
             currentBackoff = INITIAL_BACKOFF_MS
             onConnected?.invoke()
         }
@@ -244,6 +264,7 @@ object HermesWsClient {
             Log.i(TAG, "WebSocket closed: $code $reason")
             connected.set(false)
             onDisconnected?.invoke(reason)
+            _connectionStatus.value = ConnectionStatus.RECONNECTING
             scheduleReconnect()
         }
 
@@ -256,6 +277,7 @@ object HermesWsClient {
             connected.set(false)
             onError?.invoke(t)
             onDisconnected?.invoke(t.message)
+            _connectionStatus.value = ConnectionStatus.RECONNECTING
             scheduleReconnect()
         }
     }