Fix top app bar status icon contrast

The tor/proxy shield icon was tinted with hardcoded Color.Green and
Color.Red. Pure green sits on the lightColorPalette surface for the top
app bar (amber 0xFFFFDE9E) with a ~1:1 contrast ratio, so the connected
state was invisible in light theme, and neither color adapted to dark
theme. Add theme-aware connected greens to Theme.kt (dark green for the
light palette, light green for dark) and pick them with
isSystemInDarkTheme(); the disconnected state now uses
colorScheme.error, which is already theme-aware.

The relay reconnect icon drew with the hardcoded #4C4C4C fill of
relays.xml (tint Color.Unspecified), only ~2:1 on the dark theme
surface. Tint it with LocalContentColor so it matches the adjacent
relay count text; the drawable itself is left alone since the settings
screen and the navigation route icon also use it.

app/src/main/java/com/greenart7c3/nostrsigner/ui/components/AmberTopAppBar.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import android.graphics.drawable.Drawable
 import android.widget.Toast
 import androidx.compose.foundation.clickable
+import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Row
 import androidx.compose.material.icons.Icons
@@ -12,6 +13,8 @@ import androidx.compose.material3.CenterAlignedTopAppBar
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
+import androidx.compose.material3.LocalContentColor
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.PlainTooltip
 import androidx.compose.material3.Text
 import androidx.compose.material3.TooltipAnchorPosition
@@ -28,7 +31,6 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 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.platform.LocalConfiguration
 import androidx.compose.ui.platform.LocalContext
@@ -50,6 +52,8 @@ import com.greenart7c3.nostrsigner.ui.NavBackStackEntryWrapper
 import com.greenart7c3.nostrsigner.ui.navigation.Route
 import com.greenart7c3.nostrsigner.ui.navigation.routes
 import com.greenart7c3.nostrsigner.ui.navigation.title
+import com.greenart7c3.nostrsigner.ui.theme.connectedColorDark
+import com.greenart7c3.nostrsigner.ui.theme.connectedColorLight
 import com.vitorpamplona.quartz.nip46RemoteSigner.BunkerRequestConnect
 import java.util.Base64
 import kotlinx.collections.immutable.ImmutableList
@@ -107,7 +111,7 @@ fun AmberTopAppBar(
                                         Icon(
                                             imageVector = ImageVector.vectorResource(R.drawable.relays),
                                             contentDescription = context.getString(R.string.reconnect),
-                                            tint = Color.Unspecified,
+                                            tint = LocalContentColor.current,
                                         )
                                     }
                                 }
@@ -160,7 +164,11 @@ fun AmberTopAppBar(
                                                 Icon(
                                                     Icons.Outlined.Shield,
                                                     context.getString(R.string.proxy),
-                                                    tint = if (isProxyEnabled) Color.Green else Color.Red,
+                                                    tint = if (isProxyEnabled) {
+                                                        if (isSystemInDarkTheme()) connectedColorDark else connectedColorLight
+                                                    } else {
+                                                        MaterialTheme.colorScheme.error
+                                                    },
                                                 )
                                             },
                                         )

app/src/main/java/com/greenart7c3/nostrsigner/ui/theme/Theme.kt

@@ -37,6 +37,8 @@ val primaryColor = Color(0xFFFFCA62)
 val primaryVariant = Color(0xFFC8541A)
 val secondaryColor = Color(0xFFFFCA62)
 val orange = Color(0xFFFF6B00)
+val connectedColorLight = Color(0xFF1B5E20)
+val connectedColorDark = Color(0xFF81C784)
 
 private val DarkColorPalette =
     darkColorScheme(