Add 'Find it' hot/cold RSSI finder + 'Make it ring' (GATT)

- FinderScreen: live smoothed RSSI as a growing, colour-shifting proximity meter (works on silent/modified tags that refuse to ring). Fed by ScanService.finderRssi (every advert, ahead of the DB throttle).
- TrackerRinger: user-initiated GATT play-sound — VIGIL's one active operation (detection stays passive). DULT cross-vendor path (Google FMDN + DULT partners) implemented; Apple/others report gracefully pending per-ecosystem UUIDs (GATT protocol research in progress). UUIDs/opcode pending on-device verification.
- Detail sheet: 'Find it' + 'Ring it' buttons; TrackerEntity.lastMac added (needed to GATT-connect); DB version 3.
- BLUETOOTH_CONNECT was already declared for this.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0187UiEtasyowhEBYs6s9iF5

app/src/main/kotlin/org/soulstone/vigil/MainActivity.kt

@@ -7,6 +7,7 @@ import android.net.Uri
 import android.os.Build
 import android.os.Bundle
 import android.provider.Settings as AndroidSettings
+import android.widget.Toast
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.result.contract.ActivityResultContracts
@@ -17,7 +18,9 @@ import androidx.core.content.ContextCompat
 import androidx.lifecycle.lifecycleScope
 import kotlinx.coroutines.launch
 import org.soulstone.vigil.data.TrackerRepository
+import org.soulstone.vigil.data.db.TrackerEntity
 import org.soulstone.vigil.data.db.VigilDatabase
+import org.soulstone.vigil.ring.TrackerRinger
 import org.soulstone.vigil.data.settings.Settings
 import org.soulstone.vigil.service.ScanService
 import org.soulstone.vigil.ui.MainScreen
@@ -91,7 +94,8 @@ class MainActivity : ComponentActivity() {
                     },
                     onDistrust = { id ->
                         lifecycleScope.launch { repo.clearBaseline(id) }
-                    }
+                    },
+                    onRing = { tracker -> ringTracker(tracker) }
                 )
             }
         }
@@ -106,6 +110,14 @@ class MainActivity : ComponentActivity() {
         .filter { it != Manifest.permission.POST_NOTIFICATIONS }
         .all { ContextCompat.checkSelfPermission(this, it) == PackageManager.PERMISSION_GRANTED }
 
+    private fun ringTracker(tracker: TrackerEntity) {
+        Toast.makeText(this, "Trying to ring ${tracker.label}…", Toast.LENGTH_SHORT).show()
+        lifecycleScope.launch {
+            val msg = TrackerRinger.ring(this@MainActivity, tracker.lastMac, tracker.ecosystem)
+            Toast.makeText(this@MainActivity, msg, Toast.LENGTH_LONG).show()
+        }
+    }
+
     @Suppress("unused")
     private fun openAppSettings() {
         startActivity(

app/src/main/kotlin/org/soulstone/vigil/data/TrackerRepository.kt

@@ -122,7 +122,8 @@ class TrackerRepository(private val db: VigilDatabase) {
             lastRssi = obs.rssi,
             peakRssi = maxOf(existing?.peakRssi ?: -127, obs.rssi),
             distinctPlaces = assessment.distinctPlaces,
-            effectiveSightings = assessment.sightings
+            effectiveSightings = assessment.sightings,
+            lastMac = obs.mac
         )
         db.trackerDao().upsert(updated)
         RecordResult(updated, newlyAlerting)

app/src/main/kotlin/org/soulstone/vigil/data/db/VigilDatabase.kt

@@ -37,7 +37,9 @@ data class TrackerEntity(
     val lastRssi: Int = 0,
     val peakRssi: Int = -127,
     val distinctPlaces: Int = 0,
-    val effectiveSightings: Int = 0
+    val effectiveSightings: Int = 0,
+    // last-seen BLE MAC — needed to GATT-connect for "make it ring"
+    val lastMac: String = ""
 )
 
 /** One sighting of a tracker at one instant, geotagged when a fix is available. */
@@ -114,7 +116,7 @@ interface PlaceDao {
 
 @Database(
     entities = [TrackerEntity::class, SightingEntity::class, PlaceEntity::class],
-    version = 2,
+    version = 3,
     exportSchema = false
 )
 abstract class VigilDatabase : RoomDatabase() {

app/src/main/kotlin/org/soulstone/vigil/ring/TrackerRinger.kt

@@ -0,0 +1,127 @@
+package org.soulstone.vigil.ring
+
+import android.Manifest
+import android.annotation.SuppressLint
+import android.bluetooth.BluetoothDevice
+import android.bluetooth.BluetoothGatt
+import android.bluetooth.BluetoothGattCallback
+import android.bluetooth.BluetoothGattCharacteristic
+import android.bluetooth.BluetoothManager
+import android.bluetooth.BluetoothProfile
+import android.content.Context
+import android.content.pm.PackageManager
+import android.os.Build
+import android.util.Log
+import androidx.core.content.ContextCompat
+import kotlinx.coroutines.TimeoutCancellationException
+import kotlinx.coroutines.suspendCancellableCoroutine
+import kotlinx.coroutines.withTimeout
+import java.util.UUID
+import kotlin.coroutines.resume
+
+/**
+ * User-initiated "make it ring" over BLE GATT — VIGIL's ONE active operation
+ * (detection stays fully passive). Connects to a separated tracker and writes the
+ * DULT play-sound command, then disconnects.
+ *
+ * The cross-vendor DULT path covers Google Find My Device network tags and DULT
+ * partners (Chipolo/Pebblebee/eufy/Motorola). Apple AirTags use Apple's own sound
+ * service and will report "no remote-ring service" until that per-ecosystem path is
+ * added. The UUIDs/opcode below are from the DULT draft and are pending on-device
+ * verification.
+ */
+object TrackerRinger {
+
+    private const val TAG = "TrackerRinger"
+    private const val TIMEOUT_MS = 15_000L
+
+    // DULT accessory-protocol non-owner sound (IETF draft). VERIFY on-device.
+    private val DULT_SERVICE = UUID.fromString("15190001-12F4-C226-88ED-2AC5579F2A85")
+    private val DULT_NON_OWNER_CHAR = UUID.fromString("8E0C0001-1D68-FB92-BF61-48377421680E")
+    private val DULT_SOUND_START = byteArrayOf(0x00, 0x03) // opcode 0x0300 (verify endianness/format)
+
+    /** Returns a short user-facing status message. [ecosystem] is retained for the
+     *  per-ecosystem paths (e.g. Apple) still to be added. */
+    suspend fun ring(context: Context, mac: String, ecosystem: String): String {
+        if (mac.isBlank()) return "No recent address for this tracker — keep watching and try again."
+        if (!hasConnectPermission(context)) return "Grant Bluetooth (Connect) to ring trackers."
+        val adapter = (context.getSystemService(Context.BLUETOOTH_SERVICE) as? BluetoothManager)?.adapter
+            ?: return "Bluetooth unavailable."
+        if (!adapter.isEnabled) return "Turn on Bluetooth to ring trackers."
+        val device = try {
+            adapter.getRemoteDevice(mac)
+        } catch (e: IllegalArgumentException) {
+            return "Invalid device address."
+        }
+        return try {
+            withTimeout(TIMEOUT_MS) { attemptRing(context, device) }
+        } catch (e: TimeoutCancellationException) {
+            "Couldn't reach the tracker — it may be out of range, or a silent/modified tag that ignores ring commands."
+        } catch (e: Exception) {
+            Log.w(TAG, "ring failed", e)
+            "Ring failed: ${e.message}"
+        }
+    }
+
+    @SuppressLint("MissingPermission")
+    private suspend fun attemptRing(context: Context, device: BluetoothDevice): String =
+        suspendCancellableCoroutine { cont ->
+            var gatt: BluetoothGatt? = null
+            val callback = object : BluetoothGattCallback() {
+                override fun onConnectionStateChange(g: BluetoothGatt, status: Int, newState: Int) {
+                    when (newState) {
+                        BluetoothProfile.STATE_CONNECTED -> g.discoverServices()
+                        BluetoothProfile.STATE_DISCONNECTED -> {
+                            if (cont.isActive) cont.resume("Tracker disconnected before it could ring.")
+                            g.close()
+                        }
+                    }
+                }
+
+                override fun onServicesDiscovered(g: BluetoothGatt, status: Int) {
+                    val ch = g.getService(DULT_SERVICE)?.getCharacteristic(DULT_NON_OWNER_CHAR)
+                    if (ch == null) {
+                        if (cont.isActive) cont.resume("This tracker type doesn't expose a remote-ring service.")
+                        g.disconnect()
+                        return
+                    }
+                    if (!writeSound(g, ch) && cont.isActive) {
+                        cont.resume("Couldn't send the ring command.")
+                        g.disconnect()
+                    }
+                }
+
+                override fun onCharacteristicWrite(
+                    g: BluetoothGatt,
+                    ch: BluetoothGattCharacteristic,
+                    status: Int
+                ) {
+                    if (cont.isActive) cont.resume(
+                        if (status == BluetoothGatt.GATT_SUCCESS) "Ringing… listen for the tracker."
+                        else "The tracker refused the ring command."
+                    )
+                    g.disconnect()
+                }
+            }
+            gatt = device.connectGatt(context, false, callback, BluetoothDevice.TRANSPORT_LE)
+            cont.invokeOnCancellation { runCatching { gatt?.disconnect(); gatt?.close() } }
+        }
+
+    @Suppress("DEPRECATION")
+    @SuppressLint("MissingPermission")
+    private fun writeSound(g: BluetoothGatt, ch: BluetoothGattCharacteristic): Boolean =
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            g.writeCharacteristic(ch, DULT_SOUND_START, BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT) ==
+                BluetoothGatt.GATT_SUCCESS
+        } else {
+            ch.writeType = BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT
+            ch.value = DULT_SOUND_START
+            g.writeCharacteristic(ch)
+        }
+
+    private fun hasConnectPermission(context: Context): Boolean =
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            ContextCompat.checkSelfPermission(context, Manifest.permission.BLUETOOTH_CONNECT) ==
+                PackageManager.PERMISSION_GRANTED
+        } else true
+}

app/src/main/kotlin/org/soulstone/vigil/service/ScanService.kt

@@ -61,6 +61,16 @@ class ScanService : LifecycleService() {
         private val _running = MutableStateFlow(false)
         val running: StateFlow<Boolean> = _running.asStateFlow()
 
+        // Live RSSI stream for the "find it" hot/cold screen. The UI sets a target
+        // stableId; every matching advert (not the throttled DB path) updates this.
+        @Volatile private var finderTarget: String? = null
+        private val _finderRssi = MutableStateFlow<Int?>(null)
+        val finderRssi: StateFlow<Int?> = _finderRssi.asStateFlow()
+        fun setFinderTarget(id: String?) {
+            finderTarget = id
+            _finderRssi.value = null
+        }
+
         fun start(context: Context) {
             val intent = Intent(context, ScanService::class.java).apply { action = ACTION_START }
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
@@ -126,6 +136,9 @@ class ScanService : LifecycleService() {
     private fun onObservation(obs: TrackerObservation) {
         val fix = location.location.value
 
+        // Live RSSI for the "find it" screen — every advert, ahead of any throttle.
+        if (obs.stableId == finderTarget) _finderRssi.value = obs.rssi
+
         // Rotation-clone presence engine (problem #1) — fed synchronously so its
         // streaming state stays ordered. Only a CONFIRMED verdict raises a user
         // alert; softer tiers stay silent until validated on real captures.

app/src/main/kotlin/org/soulstone/vigil/ui/MainScreen.kt

@@ -1,6 +1,14 @@
 package org.soulstone.vigil.ui
 
 import android.text.format.DateUtils
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.material.icons.filled.NotificationsActive
+import androidx.compose.material.icons.filled.Sensors
+import androidx.compose.material3.FilledTonalButton
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.ui.graphics.lerp
+import org.soulstone.vigil.service.ScanService
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
@@ -73,9 +81,11 @@ fun MainScreen(
     onStartStop: () -> Unit,
     onSetSensitivity: (Sensitivity) -> Unit,
     onApprove: (String, Boolean) -> Unit,
-    onDistrust: (String) -> Unit
+    onDistrust: (String) -> Unit,
+    onRing: (TrackerEntity) -> Unit
 ) {
     var detail by remember { mutableStateOf<TrackerEntity?>(null) }
+    var finding by remember { mutableStateOf<TrackerEntity?>(null) }
 
     val now = System.currentTimeMillis()
     val active = trackers
@@ -195,10 +205,20 @@ fun MainScreen(
             TrackerDetail(
                 t,
                 onApprove = { id, a -> onApprove(id, a); detail = null },
-                onDistrust = { id -> onDistrust(id); detail = null }
+                onDistrust = { id -> onDistrust(id); detail = null },
+                onFind = { dev -> ScanService.setFinderTarget(dev.stableId); finding = dev; detail = null },
+                onRing = onRing
             )
         }
     }
+
+    finding?.let { dev ->
+        FinderScreen(
+            dev,
+            onRing = onRing,
+            onClose = { ScanService.setFinderTarget(null); finding = null }
+        )
+    }
 }
 
 @Composable
@@ -335,7 +355,9 @@ private fun TrackerCard(
 private fun TrackerDetail(
     t: TrackerEntity,
     onApprove: (String, Boolean) -> Unit,
-    onDistrust: (String) -> Unit
+    onDistrust: (String) -> Unit,
+    onFind: (TrackerEntity) -> Unit,
+    onRing: (TrackerEntity) -> Unit
 ) {
     val status = statusOf(t)
     Column(Modifier.fillMaxWidth().padding(24.dp)) {
@@ -366,6 +388,19 @@ private fun TrackerDetail(
             color = MaterialTheme.colorScheme.onSurfaceVariant
         )
         Spacer(Modifier.height(20.dp))
+        Row(Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+            FilledTonalButton(onClick = { onFind(t) }, modifier = Modifier.weight(1f)) {
+                Icon(Icons.Filled.Sensors, null, modifier = Modifier.size(18.dp))
+                Spacer(Modifier.size(6.dp))
+                Text("Find it")
+            }
+            FilledTonalButton(onClick = { onRing(t) }, modifier = Modifier.weight(1f)) {
+                Icon(Icons.Filled.NotificationsActive, null, modifier = Modifier.size(18.dp))
+                Spacer(Modifier.size(6.dp))
+                Text("Ring it")
+            }
+        }
+        Spacer(Modifier.height(12.dp))
         when (status) {
             TrackerStatus.SAFE_APPROVED ->
                 Button(onClick = { onApprove(t.stableId, false) }, modifier = Modifier.fillMaxWidth()) {
@@ -392,6 +427,78 @@ private fun DetailRow(label: String, value: String) {
     }
 }
 
+/** Passive hot/cold finder — smoothed live RSSI as a growing, colour-shifting
+ *  proximity meter. Works even on silent/modified tags that refuse to ring. */
+@Composable
+private fun FinderScreen(t: TrackerEntity, onRing: (TrackerEntity) -> Unit, onClose: () -> Unit) {
+    val rssi by ScanService.finderRssi.collectAsState()
+    val smoothed = remember { mutableStateOf(-100f) }
+    LaunchedEffect(rssi) { rssi?.let { smoothed.value = 0.35f * it + 0.65f * smoothed.value } }
+    val hasSignal = rssi != null
+    val p = ((smoothed.value + 100f) / 60f).coerceIn(0f, 1f)  // -100 dBm..-40 dBm -> 0..1
+    val label = when {
+        !hasSignal -> "Searching… walk around"
+        p > 0.8f -> "Right here"
+        p > 0.6f -> "Very close"
+        p > 0.4f -> "Close"
+        p > 0.2f -> "Getting warmer"
+        else -> "Far"
+    }
+    val color = lerp(VigilRed, VigilGreen, p)
+
+    Surface(Modifier.fillMaxSize(), color = MaterialTheme.colorScheme.background) {
+        Column(
+            Modifier.fillMaxSize().padding(24.dp),
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.Center
+        ) {
+            Text(
+                ecosystemDisplay(t.ecosystem),
+                style = MaterialTheme.typography.titleLarge,
+                fontWeight = FontWeight.Bold
+            )
+            Spacer(Modifier.height(32.dp))
+            Box(
+                Modifier.size((120 + p * 160).dp).clip(CircleShape).background(
+                    if (hasSignal) color.copy(alpha = 0.25f) else MaterialTheme.colorScheme.surfaceVariant
+                ),
+                contentAlignment = Alignment.Center
+            ) {
+                Icon(
+                    Icons.Filled.Sensors, null,
+                    tint = if (hasSignal) color else MaterialTheme.colorScheme.onSurfaceVariant,
+                    modifier = Modifier.size(64.dp)
+                )
+            }
+            Spacer(Modifier.height(32.dp))
+            Text(
+                label,
+                style = MaterialTheme.typography.headlineSmall,
+                fontWeight = FontWeight.Bold,
+                color = if (hasSignal) color else MaterialTheme.colorScheme.onSurfaceVariant
+            )
+            Text(
+                if (hasSignal) "$rssi dBm" else "no signal yet",
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+            Spacer(Modifier.height(40.dp))
+            Button(onClick = { onRing(t) }, modifier = Modifier.fillMaxWidth().height(52.dp)) {
+                Icon(Icons.Filled.NotificationsActive, null)
+                Spacer(Modifier.size(8.dp))
+                Text("Make it ring")
+            }
+            Spacer(Modifier.height(8.dp))
+            TextButton(onClick = onClose, modifier = Modifier.fillMaxWidth()) { Text("Done") }
+            Spacer(Modifier.height(12.dp))
+            Text(
+                "If it won't ring, it may be a silent or modified tracker — use the signal above to home in on it.",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+        }
+    }
+}
+
 // ---- pure helpers ----------------------------------------------------------
 
 private const val ACTIVE_WINDOW_MS = 10 * 60_000L  // trackers not seen this recently drop off "Active"