feat(track): record which devices are paired, and report it on upload

The app knew about bonded devices only in passing - syncPairedDevices marked
them tracked and threw the bond state away - so nothing downstream could tell
a paired device from one merely seen. Adds devices.paired (schema 17), set
from ACTION_BOND_STATE_CHANGED and from the bonded list at startup, and sends
it as a `paired` column on every uploaded row.

The flag is its own column rather than inferred from is_tracked, which answers
a different question: a device can be tracked without ever having been paired.

syncPairedDevices clears the flag before re-asserting it from getBondedDevices.
A device unpaired while the service was dead never broadcast BOND_NONE, so the
bonded list is the only reliable answer at startup, and without the clear such
a device would stay marked paired forever.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app/src/main/java/com/wytehat/btlogger/BluetoothTrackingService.java

@@ -117,11 +117,14 @@ public class BluetoothTrackingService extends Service implements LocationListene
             } else if (BluetoothDevice.ACTION_BOND_STATE_CHANGED.equals(action)) {
                 int state = intent.getIntExtra(BluetoothDevice.EXTRA_BOND_STATE,
 											   BluetoothDevice.ERROR);
-                if (state == BluetoothDevice.BOND_BONDED)
+                if (state == BluetoothDevice.BOND_BONDED) {
                     db.markTracked(address, broadcastName);
-                else if (state == BluetoothDevice.BOND_NONE)
+                    db.setPaired(address, true);
+                } else if (state == BluetoothDevice.BOND_NONE) {
+                    db.setPaired(address, false);
                     db.disconnected(address, broadcastName, now, fix,
 									"Manual / Intentional Disconnect");
+                }
             }
             resolveVendor(address, -1);
             notifyChanged();
@@ -370,10 +373,16 @@ public class BluetoothTrackingService extends Service implements LocationListene
     private void syncPairedDevices() {
         if (bluetooth == null) return;
         try {
+            // The bonded list is the whole truth, so the flag is cleared first:
+            // a device unpaired while the service was dead sent no BOND_NONE
+            // broadcast, and would otherwise stay marked as paired forever.
+            db.clearPaired();
+
             for (BluetoothDevice device : bluetooth.getBondedDevices()) {
                 String value = address(device);
                 if (value != null) {
                     db.markTracked(value, name(device));
+                    db.setPaired(value, true);
                     resolveVendor(value, -1);
                 }
             }

app/src/main/java/com/wytehat/btlogger/DeviceRecord.java

@@ -14,6 +14,9 @@ public class DeviceRecord {
     public int locationLocked;
     public int showTrail = 1;
     public int trackBroadcast;
+
+    /** 1 when this device is bonded to the phone. */
+    public int paired;
     public String reason;
     public String photoUri;
     public String iconPreset;

app/src/main/java/com/wytehat/btlogger/ServerUploader.java

@@ -51,7 +51,7 @@ public final class ServerUploader {
 
     /** Columns the server's importer recognises without any aliasing. */
     private static final String HEADER =
-        "mac_address,device_name,device_class,rssi,latitude,longitude,timestamp";
+        "mac_address,device_name,device_class,rssi,latitude,longitude,timestamp,paired";
 
     private static final int CONNECT_TIMEOUT_MS = 20000;
     private static final int READ_TIMEOUT_MS = 60000;
@@ -177,7 +177,8 @@ public final class ServerUploader {
                     record.latitude, record.longitude,
                     record.updatedAt > 0
                         ? record.updatedAt
-                        : System.currentTimeMillis());
+                        : System.currentTimeMillis(),
+                    record.paired == 1);
             }
 
             List<LocationPoint> history = database.history(record.address, 0L);
@@ -198,7 +199,8 @@ public final class ServerUploader {
                 // empty rather than repeating the device's latest reading,
                 // which was measured somewhere else entirely.
                 appendRow(csv, stamp, record.address, name, category, "",
-                    point.latitude, point.longitude, time);
+                    point.latitude, point.longitude, time,
+                    record.paired == 1);
             }
         }
 
@@ -208,7 +210,7 @@ public final class ServerUploader {
     private static void appendRow(StringBuilder csv, SimpleDateFormat stamp,
                                   String mac, String name, String category,
                                   String rssi, double latitude,
-                                  double longitude, long time) {
+                                  double longitude, long time, boolean paired) {
 
         csv.append(field(mac)).append(',')
             .append(field(name)).append(',')
@@ -216,7 +218,8 @@ public final class ServerUploader {
             .append(rssi).append(',')
             .append(latitude).append(',')
             .append(longitude).append(',')
-            .append(stamp.format(new Date(time)))
+            .append(stamp.format(new Date(time))).append(',')
+            .append(paired ? "1" : "0")
             .append('\n');
     }
 

app/src/main/java/com/wytehat/btlogger/TrackerDatabase.java

@@ -11,7 +11,7 @@ import java.util.Locale;
 
 public class TrackerDatabase extends SQLiteOpenHelper {
     private static final String DB_NAME = "bluetooth_tracker.db";
-    private static final int DB_VERSION = 16;
+    private static final int DB_VERSION = 17;
 
     public TrackerDatabase(Context context) {
         super(context, DB_NAME, null, DB_VERSION);
@@ -47,7 +47,7 @@ public class TrackerDatabase extends SQLiteOpenHelper {
             "reason TEXT,updated_at INTEGER DEFAULT 0,photo_uri TEXT,icon_preset TEXT DEFAULT 'bag'," +
             "gps_polling_rate INTEGER DEFAULT 900000,pin_color TEXT DEFAULT '#E53935'," +
             "tracking_priority INTEGER DEFAULT 15,photo_path TEXT,device_gps_interval INTEGER DEFAULT 15," +
-            "is_tracked INTEGER DEFAULT 0,custom_name TEXT,broadcast_name TEXT,vendor_name TEXT,tx_power_1m INTEGER DEFAULT -59,path_loss_exponent REAL DEFAULT 2.7,last_rssi_at INTEGER DEFAULT 0,device_category TEXT,category_manual INTEGER DEFAULT 0,vendor_manual INTEGER DEFAULT 0,map_enabled INTEGER DEFAULT 0,live_enabled INTEGER DEFAULT 0,location_locked INTEGER DEFAULT 0,show_trail INTEGER DEFAULT 1,track_broadcast INTEGER DEFAULT 0)");
+            "is_tracked INTEGER DEFAULT 0,custom_name TEXT,broadcast_name TEXT,vendor_name TEXT,tx_power_1m INTEGER DEFAULT -59,path_loss_exponent REAL DEFAULT 2.7,last_rssi_at INTEGER DEFAULT 0,device_category TEXT,category_manual INTEGER DEFAULT 0,vendor_manual INTEGER DEFAULT 0,map_enabled INTEGER DEFAULT 0,live_enabled INTEGER DEFAULT 0,location_locked INTEGER DEFAULT 0,show_trail INTEGER DEFAULT 1,track_broadcast INTEGER DEFAULT 0,paired INTEGER DEFAULT 0)");
         createSupportingTables(db);
         seedVendors(db);
     }
@@ -103,6 +103,8 @@ public class TrackerDatabase extends SQLiteOpenHelper {
         if (oldVersion < 15) seedVendors(db);
         if (oldVersion < 16)
             addColumn(db, "ALTER TABLE location_history ADD COLUMN event TEXT");
+        if (oldVersion < 17)
+            addColumn(db, "ALTER TABLE devices ADD COLUMN paired INTEGER DEFAULT 0");
     }
 
     private void addColumn(SQLiteDatabase db, String sql) {
@@ -331,6 +333,24 @@ public class TrackerDatabase extends SQLiteOpenHelper {
         getWritableDatabase().update("devices", values, "address=?", new String[] { address });
     }
 
+    /**
+     * Records whether this device is bonded to the phone.
+     *
+     * Kept as its own column rather than inferred from is_tracked: a device can
+     * be tracked without ever having been paired, and the two answer different
+     * questions.
+     */
+    /** Clears the flag on every device, before the bonded list re-asserts it. */
+    public synchronized void clearPaired() {
+        ContentValues values = new ContentValues(); values.put("paired", 0);
+        getWritableDatabase().update("devices", values, null, null);
+    }
+
+    public synchronized void setPaired(String address, boolean paired) {
+        ContentValues values = new ContentValues(); values.put("paired", paired ? 1 : 0);
+        getWritableDatabase().update("devices", values, "address=?", new String[] { address });
+    }
+
     public synchronized void setMapEnabled(String address, boolean enabled) {
         ContentValues values = new ContentValues(); values.put("map_enabled", enabled ? 1 : 0);
         getWritableDatabase().update("devices", values, "address=?", new String[] { address });
@@ -517,6 +537,7 @@ public class TrackerDatabase extends SQLiteOpenHelper {
         r.locationLocked = integer(c, "location_locked");
         r.showTrail = integer(c, "show_trail");
         r.trackBroadcast = integer(c, "track_broadcast");
+        r.paired = integer(c, "paired");
         r.connected = integer(c, "connected");
         r.connectedAt = number(c, "connected_at");
         r.disconnectedAt = number(c, "disconnected_at");