Survivor side (3/4): in-app co-movement trail

TrailView: an offline schematic of a tracker's geotagged sightings (points + path, scaled to fit) shown on the tracker detail sheet when there are >=2 located sightings. Start point green, latest peach. Not a real map (VIGIL has no network) — the GPX export from Phase 2 opens in one. Release 0.1.10.

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

app/build.gradle.kts

@@ -13,8 +13,8 @@ android {
         applicationId = "org.soulstone.vigil"
         minSdk = 26
         targetSdk = 35
-        versionCode = 9
-        versionName = "0.1.8"
+        versionCode = 11
+        versionName = "0.1.10"
     }
 
     // Fixed debug keystore committed to the repo (a debug key is non-secret — its

app/src/main/AndroidManifest.xml

@@ -67,5 +67,16 @@
             android:enabled="true"
             android:exported="false"
             android:foregroundServiceType="connectedDevice|location" />
+
+        <!-- Shares exported evidence files (report + GPX) with other apps. No network. -->
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="${applicationId}.fileprovider"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/file_paths" />
+        </provider>
     </application>
 </manifest>

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

@@ -17,14 +17,17 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.core.content.ContextCompat
+import androidx.core.content.FileProvider
 import androidx.lifecycle.lifecycleScope
 import kotlinx.coroutines.launch
+import java.io.File
 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.HistoryScreen
 import org.soulstone.vigil.ui.MainScreen
 import org.soulstone.vigil.ui.OnboardingScreen
 import org.soulstone.vigil.ui.SafetyScreen
@@ -74,12 +77,22 @@ class MainActivity : ComponentActivity() {
             VigilTheme {
                 val onboarded by settings.onboarded.collectAsState()
                 var showSafety by remember { mutableStateOf(false) }
+                var showHistory by remember { mutableStateOf(false) }
                 when {
                     !onboarded -> OnboardingScreen(onFinish = {
                         settings.setOnboarded(true)
                         if (!hasEssentialPermissions()) permissionLauncher.launch(requiredPermissions)
                     })
                     showSafety -> SafetyScreen(onBack = { showSafety = false })
+                    showHistory -> {
+                        val alerts by repo.observeAlerts().collectAsState(initial = emptyList())
+                        HistoryScreen(
+                            alerts = alerts,
+                            onExport = { exportEvidence() },
+                            onClear = { lifecycleScope.launch { repo.clearAlerts() } },
+                            onBack = { showHistory = false }
+                        )
+                    }
                     else -> {
                         val running by ScanService.running.collectAsState()
                         val trackers by repo.observeTrackers().collectAsState(initial = emptyList())
@@ -110,7 +123,9 @@ class MainActivity : ComponentActivity() {
                             },
                             onRing = { tracker -> ringTracker(tracker) },
                             onClearAll = { lifecycleScope.launch { repo.clearAll() } },
-                            onOpenSafety = { showSafety = true }
+                            onOpenSafety = { showSafety = true },
+                            onOpenHistory = { showHistory = true },
+                            loadTrail = { id -> repo.trailFor(id) }
                         )
                     }
                 }
@@ -135,6 +150,34 @@ class MainActivity : ComponentActivity() {
         }
     }
 
+    private fun exportEvidence() {
+        lifecycleScope.launch {
+            val report = repo.buildTextReport()
+            if (report == null) {
+                Toast.makeText(this@MainActivity, "No alerts to export yet.", Toast.LENGTH_SHORT).show()
+                return@launch
+            }
+            runCatching {
+                val dir = File(cacheDir, "exports").apply { mkdirs() }
+                val txt = File(dir, "vigil-report.txt").apply { writeText(report) }
+                val gpx = File(dir, "vigil-track.gpx").apply { writeText(repo.buildGpx()) }
+                val auth = "$packageName.fileprovider"
+                val uris = arrayListOf(
+                    FileProvider.getUriForFile(this@MainActivity, auth, txt),
+                    FileProvider.getUriForFile(this@MainActivity, auth, gpx)
+                )
+                val share = Intent(Intent.ACTION_SEND_MULTIPLE).apply {
+                    type = "*/*"
+                    putParcelableArrayListExtra(Intent.EXTRA_STREAM, uris)
+                    addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+                }
+                startActivity(Intent.createChooser(share, "Export VIGIL evidence"))
+            }.onFailure {
+                Toast.makeText(this@MainActivity, "Export failed: ${it.message}", Toast.LENGTH_LONG).show()
+            }
+        }
+    }
+
     @Suppress("unused")
     private fun openAppSettings() {
         startActivity(

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

@@ -3,6 +3,7 @@ package org.soulstone.vigil.data
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
+import org.soulstone.vigil.data.db.AlertEntity
 import org.soulstone.vigil.data.db.SightingEntity
 import org.soulstone.vigil.data.db.TrackerEntity
 import org.soulstone.vigil.data.db.VigilDatabase
@@ -11,8 +12,14 @@ import org.soulstone.vigil.detect.CoMovementEvaluator
 import org.soulstone.vigil.model.RiskState
 import org.soulstone.vigil.model.SeparatedState
 import org.soulstone.vigil.model.Sensitivity
+import org.soulstone.vigil.model.TrackerEcosystem
 import org.soulstone.vigil.model.TrackerObservation
+import org.soulstone.vigil.model.TrailPoint
 import org.soulstone.vigil.util.Geohash
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
 
 /**
  * The temporal core. Persists sightings, maintains the learned baseline, and runs
@@ -133,10 +140,98 @@ class TrackerRepository(private val db: VigilDatabase) {
             lastMac = obs.mac
         )
         db.trackerDao().upsert(updated)
+        if (newlyAlerting) {
+            db.alertDao().insert(
+                AlertEntity(
+                    trackerId = obs.stableId,
+                    ecosystem = obs.ecosystem.name,
+                    label = obs.label,
+                    timestamp = now,
+                    distinctPlaces = assessment.distinctPlaces,
+                    peakRssi = updated.peakRssi,
+                    lat = lat, lon = lon
+                )
+            )
+        }
         RecordResult(updated, newlyAlerting)
     }
 
+    fun observeAlerts(): Flow<List<AlertEntity>> = db.alertDao().observeAll()
+
+    suspend fun clearAlerts() = db.alertDao().clear()
+
+    /** Geotagged sightings of one tracker, in time order, for the in-app trail. */
+    suspend fun trailFor(id: String): List<TrailPoint> =
+        db.sightingDao().allFor(id).mapNotNull { s ->
+            val la = s.lat; val lo = s.lon
+            if (la != null && lo != null) TrailPoint(la, lo) else null
+        }
+
+    /** Human-readable evidence report; null if there are no alerts yet. */
+    suspend fun buildTextReport(): String? {
+        val alerts = db.alertDao().all()
+        if (alerts.isEmpty()) return null
+        val fmt = SimpleDateFormat("yyyy-MM-dd HH:mm:ss z", Locale.US)
+        val sb = StringBuilder()
+        sb.appendLine("VIGIL — tracker evidence report")
+        sb.appendLine("Generated: ${fmt.format(Date())}")
+        sb.appendLine("Times are this phone's local time; locations are approximate (phone GPS).")
+        sb.appendLine("=".repeat(52))
+        for ((trackerId, group) in alerts.groupBy { it.trackerId }) {
+            val head = group.first()
+            sb.appendLine()
+            sb.appendLine("${ecoLabel(head.ecosystem)} — ${head.label}")
+            sb.appendLine("Identity: $trackerId")
+            sb.appendLine("Flagged ${group.size} time(s):")
+            for (a in group) {
+                val where = if (a.lat != null && a.lon != null) "%.5f, %.5f".format(a.lat, a.lon) else "no location"
+                sb.appendLine("  - ${fmt.format(Date(a.timestamp))} : ${a.distinctPlaces} places, peak ${a.peakRssi} dBm, at $where")
+            }
+            val geo = db.sightingDao().allFor(trackerId).filter { it.lat != null && it.lon != null }
+            if (geo.isNotEmpty()) {
+                sb.appendLine("  Seen with you at ${geo.size} location(s):")
+                for (s in geo) {
+                    sb.appendLine("    ${fmt.format(Date(s.timestamp))}  ${"%.5f, %.5f".format(s.lat, s.lon)}  ${s.rssi} dBm")
+                }
+            }
+        }
+        sb.appendLine()
+        sb.appendLine("=".repeat(52))
+        sb.appendLine("Recorded by VIGIL, an offline anti-tracking app — a log of Bluetooth trackers detected moving with this phone.")
+        return sb.toString()
+    }
+
+    /** GPX of every geotagged sighting, to open in a maps app. */
+    suspend fun buildGpx(): String {
+        val fmt = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.US).apply {
+            timeZone = TimeZone.getTimeZone("UTC")
+        }
+        val sb = StringBuilder()
+        sb.appendLine("""<?xml version="1.0" encoding="UTF-8"?>""")
+        sb.appendLine("""<gpx version="1.1" creator="VIGIL" xmlns="http://www.topografix.com/GPX/1/1">""")
+        for (s in db.sightingDao().allGeotagged()) {
+            sb.appendLine("""  <wpt lat="${s.lat}" lon="${s.lon}">""")
+            sb.appendLine("    <time>${fmt.format(Date(s.timestamp))}</time>")
+            sb.appendLine("    <name>${trackerShortName(s.trackerId)} ${s.rssi}dBm</name>")
+            sb.appendLine("  </wpt>")
+        }
+        sb.appendLine("</gpx>")
+        return sb.toString()
+    }
+
     companion object {
         const val RETENTION_DAYS = 14
     }
 }
+
+private fun ecoLabel(name: String): String =
+    runCatching { TrackerEcosystem.valueOf(name).display }.getOrDefault(name)
+
+private fun trackerShortName(stableId: String): String = when (stableId.substringBefore(':')) {
+    "apple" -> "AppleFindMy"
+    "fmdn" -> "GoogleFMD"
+    "samsung" -> "SmartTag"
+    "tile" -> "Tile"
+    "dult" -> "DULT"
+    else -> "Tracker"
+}

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

@@ -68,6 +68,21 @@ data class PlaceEntity(
     val anchor: Boolean = false
 )
 
+/** A recorded alert — when a tracker first crossed into ALERTING. Kept for the
+ *  history list and the evidence export. */
+@Entity(tableName = "alerts")
+data class AlertEntity(
+    @PrimaryKey(autoGenerate = true) val id: Long = 0,
+    val trackerId: String,
+    val ecosystem: String,
+    val label: String,
+    val timestamp: Long,
+    val distinctPlaces: Int,
+    val peakRssi: Int,
+    val lat: Double? = null,
+    val lon: Double? = null
+)
+
 @Dao
 interface TrackerDao {
     @Query("SELECT * FROM trackers WHERE stableId = :id")
@@ -104,6 +119,12 @@ interface SightingDao {
     @Query("SELECT * FROM sightings WHERE trackerId = :id AND timestamp >= :since ORDER BY timestamp")
     suspend fun recentFor(id: String, since: Long): List<SightingEntity>
 
+    @Query("SELECT * FROM sightings WHERE trackerId = :id ORDER BY timestamp")
+    suspend fun allFor(id: String): List<SightingEntity>
+
+    @Query("SELECT * FROM sightings WHERE lat IS NOT NULL ORDER BY timestamp")
+    suspend fun allGeotagged(): List<SightingEntity>
+
     @Query("DELETE FROM sightings WHERE timestamp < :cutoff")
     suspend fun prune(cutoff: Long)
 
@@ -120,15 +141,31 @@ interface PlaceDao {
     suspend fun upsert(place: PlaceEntity)
 }
 
+@Dao
+interface AlertDao {
+    @Insert
+    suspend fun insert(alert: AlertEntity)
+
+    @Query("SELECT * FROM alerts ORDER BY timestamp DESC")
+    fun observeAll(): Flow<List<AlertEntity>>
+
+    @Query("SELECT * FROM alerts ORDER BY timestamp DESC")
+    suspend fun all(): List<AlertEntity>
+
+    @Query("DELETE FROM alerts")
+    suspend fun clear()
+}
+
 @Database(
-    entities = [TrackerEntity::class, SightingEntity::class, PlaceEntity::class],
-    version = 3,
+    entities = [TrackerEntity::class, SightingEntity::class, PlaceEntity::class, AlertEntity::class],
+    version = 4,
     exportSchema = false
 )
 abstract class VigilDatabase : RoomDatabase() {
     abstract fun trackerDao(): TrackerDao
     abstract fun sightingDao(): SightingDao
     abstract fun placeDao(): PlaceDao
+    abstract fun alertDao(): AlertDao
 
     companion object {
         @Volatile private var INSTANCE: VigilDatabase? = null

app/src/main/kotlin/org/soulstone/vigil/model/Types.kt

@@ -37,3 +37,6 @@ enum class TrackerStatus { SAFE_APPROVED, SAFE_BASELINE, OBSERVED, SUSPICIOUS, A
 
 /** Detection sensitivity — trades time-to-alert against false positives. */
 enum class Sensitivity { HIGH, MEDIUM, LOW }
+
+/** A geotagged point where a tracker was seen, for the in-app co-movement trail. */
+data class TrailPoint(val lat: Double, val lon: Double)

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

@@ -0,0 +1,97 @@
+package org.soulstone.vigil.ui
+
+import android.text.format.DateUtils
+import androidx.activity.compose.BackHandler
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.Share
+import androidx.compose.material3.Button
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
+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.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import org.soulstone.vigil.data.db.AlertEntity
+import org.soulstone.vigil.model.TrackerEcosystem
+
+/** Log of past alerts, with a one-tap evidence export (report + GPX). */
+@Composable
+fun HistoryScreen(
+    alerts: List<AlertEntity>,
+    onExport: () -> Unit,
+    onClear: () -> Unit,
+    onBack: () -> Unit
+) {
+    BackHandler(onBack = onBack)
+    Surface(Modifier.fillMaxSize(), color = MaterialTheme.colorScheme.background) {
+        Column(Modifier.fillMaxSize().padding(16.dp)) {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                IconButton(onClick = onBack) { Icon(Icons.Filled.ArrowBack, "Back") }
+                Spacer(Modifier.size(4.dp))
+                Text("Alert history", style = MaterialTheme.typography.titleLarge, fontWeight = FontWeight.Bold)
+            }
+            Spacer(Modifier.height(12.dp))
+            Row(Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                Button(onClick = onExport, modifier = Modifier.weight(1f)) {
+                    Icon(Icons.Filled.Share, null, modifier = Modifier.size(18.dp))
+                    Spacer(Modifier.size(6.dp))
+                    Text("Export evidence")
+                }
+                OutlinedButton(onClick = onClear, enabled = alerts.isNotEmpty()) { Text("Clear") }
+            }
+            Spacer(Modifier.height(6.dp))
+            Text(
+                "Export saves a timestamped report and a GPX track (open it in a maps app). Files stay on your phone until you share them.",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+            Spacer(Modifier.height(16.dp))
+            if (alerts.isEmpty()) {
+                Text(
+                    "No alerts yet. When a tracker is confirmed following you, it'll be logged here.",
+                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+            } else {
+                LazyColumn(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                    items(alerts, key = { it.id }) { a -> AlertRow(a) }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun AlertRow(a: AlertEntity) {
+    Card(Modifier.fillMaxWidth(), colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surface)) {
+        Column(Modifier.padding(14.dp)) {
+            Text(ecoName(a.ecosystem), fontWeight = FontWeight.SemiBold)
+            Text(
+                "${a.distinctPlaces} places · peak ${a.peakRssi} dBm · ${rel(a.timestamp)}",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+        }
+    }
+}
+
+private fun ecoName(name: String) = runCatching { TrackerEcosystem.valueOf(name).display }.getOrDefault(name)
+private fun rel(ts: Long) = DateUtils.getRelativeTimeSpanString(ts, System.currentTimeMillis(), DateUtils.MINUTE_IN_MILLIS).toString()

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

@@ -12,6 +12,7 @@ import androidx.compose.ui.graphics.lerp
 import androidx.compose.ui.res.painterResource
 import org.soulstone.vigil.service.ScanService
 import androidx.compose.foundation.Image
+import androidx.compose.foundation.Canvas
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
@@ -33,6 +34,7 @@ import androidx.compose.material.icons.filled.CheckCircle
 import androidx.compose.material.icons.filled.DeleteSweep
 import androidx.compose.material.icons.filled.GppMaybe
 import androidx.compose.material.icons.filled.HealthAndSafety
+import androidx.compose.material.icons.filled.History
 import androidx.compose.material.icons.filled.Lock
 import androidx.compose.material.icons.filled.Radar
 import androidx.compose.material.icons.filled.Shield
@@ -59,11 +61,13 @@ import androidx.compose.material3.rememberModalBottomSheetState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.produceState
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.text.font.FontWeight
@@ -75,6 +79,7 @@ import org.soulstone.vigil.model.Sensitivity
 import org.soulstone.vigil.model.TrackerEcosystem
 import org.soulstone.vigil.R
 import org.soulstone.vigil.model.TrackerStatus
+import org.soulstone.vigil.model.TrailPoint
 import org.soulstone.vigil.ui.theme.VigilGreen
 import org.soulstone.vigil.ui.theme.VigilPeach
 import org.soulstone.vigil.ui.theme.VigilRed
@@ -92,7 +97,9 @@ fun MainScreen(
     onDistrust: (String) -> Unit,
     onRing: (TrackerEntity) -> Unit,
     onClearAll: () -> Unit,
-    onOpenSafety: () -> Unit
+    onOpenSafety: () -> Unit,
+    onOpenHistory: () -> Unit,
+    loadTrail: suspend (String) -> List<TrailPoint>
 ) {
     var detail by remember { mutableStateOf<TrackerEntity?>(null) }
     var finding by remember { mutableStateOf<TrackerEntity?>(null) }
@@ -121,6 +128,13 @@ fun MainScreen(
                     }
                 },
                 actions = {
+                    IconButton(onClick = onOpenHistory) {
+                        Icon(
+                            Icons.Filled.History,
+                            contentDescription = "Alert history",
+                            tint = MaterialTheme.colorScheme.onSurfaceVariant
+                        )
+                    }
                     IconButton(onClick = onOpenSafety) {
                         Icon(
                             Icons.Filled.HealthAndSafety,
@@ -238,7 +252,8 @@ fun MainScreen(
                 onDistrust = { id -> onDistrust(id); detail = null },
                 onFind = { dev -> ScanService.setFinderTarget(dev.stableId); finding = dev; detail = null },
                 onRing = onRing,
-                onSafety = { onOpenSafety(); detail = null }
+                onSafety = { onOpenSafety(); detail = null },
+                loadTrail = loadTrail
             )
         }
     }
@@ -389,7 +404,8 @@ private fun TrackerDetail(
     onDistrust: (String) -> Unit,
     onFind: (TrackerEntity) -> Unit,
     onRing: (TrackerEntity) -> Unit,
-    onSafety: () -> Unit
+    onSafety: () -> Unit,
+    loadTrail: suspend (String) -> List<TrailPoint>
 ) {
     val status = statusOf(t)
     Column(Modifier.fillMaxWidth().padding(24.dp)) {
@@ -431,6 +447,25 @@ private fun TrackerDetail(
             style = MaterialTheme.typography.bodyMedium,
             color = MaterialTheme.colorScheme.onSurfaceVariant
         )
+
+        val trail by produceState(initialValue = emptyList<TrailPoint>(), t.stableId) { value = loadTrail(t.stableId) }
+        if (trail.size >= 2) {
+            Spacer(Modifier.height(18.dp))
+            Text("Where it's moved with you", style = MaterialTheme.typography.labelLarge, fontWeight = FontWeight.SemiBold)
+            Spacer(Modifier.height(8.dp))
+            TrailView(
+                trail,
+                Modifier.fillMaxWidth().height(150.dp).clip(RoundedCornerShape(12.dp))
+                    .background(MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.5f))
+            )
+            Text(
+                "A schematic of the ${trail.size} points it was seen — not a real map. Use Export for that.",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.padding(top = 6.dp)
+            )
+        }
+
         Spacer(Modifier.height(20.dp))
         Row(Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.spacedBy(8.dp)) {
             FilledTonalButton(onClick = { onFind(t) }, modifier = Modifier.weight(1f)) {
@@ -545,6 +580,38 @@ private fun FinderScreen(t: TrackerEntity, onRing: (TrackerEntity) -> Unit, onCl
     }
 }
 
+/** Offline schematic of a tracker's geotagged sightings — points + path, scaled
+ *  to fit. Not a real map (VIGIL has no network); the GPX export opens in one. */
+@Composable
+private fun TrailView(points: List<TrailPoint>, modifier: Modifier = Modifier) {
+    val line = Color(0xFF89B4FA)
+    val startC = Color(0xFFA6E3A1)
+    val endC = Color(0xFFFAB387)
+    Canvas(modifier) {
+        if (points.size < 2) return@Canvas
+        val pad = 18f
+        val minLat = points.minOf { it.lat }; val maxLat = points.maxOf { it.lat }
+        val minLon = points.minOf { it.lon }; val maxLon = points.maxOf { it.lon }
+        val rLat = (maxLat - minLat).let { if (it > 1e-9) it else 1e-9 }
+        val rLon = (maxLon - minLon).let { if (it > 1e-9) it else 1e-9 }
+        val w = size.width - 2 * pad
+        val h = size.height - 2 * pad
+        val pts = points.map { p ->
+            Offset(
+                pad + ((p.lon - minLon) / rLon).toFloat() * w,
+                pad + (1f - ((p.lat - minLat) / rLat).toFloat()) * h
+            )
+        }
+        for (i in 0 until pts.size - 1) {
+            drawLine(line.copy(alpha = 0.55f), pts[i], pts[i + 1], strokeWidth = 3f)
+        }
+        pts.forEachIndexed { i, o ->
+            val c = if (i == 0) startC else if (i == pts.lastIndex) endC else line
+            drawCircle(c, radius = if (i == 0 || i == pts.lastIndex) 6f else 4f, center = o)
+        }
+    }
+}
+
 // ---- pure helpers ----------------------------------------------------------
 
 private const val ACTIVE_WINDOW_MS = 10 * 60_000L  // trackers not seen this recently drop off "Active"

app/src/main/res/xml/file_paths.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths>
+    <cache-path name="exports" path="exports/" />
+</paths>