Add 'Clear all' button to wipe the tracker list

Trash action in the top bar (shown when the list is non-empty) clears all tracker rows + sighting history via repo.clearAll(). Devices re-populate as they're re-detected; learned baseline places are kept. Release 0.1.4.

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/data/TrackerRepository.kt

@@ -44,6 +44,13 @@ class TrackerRepository(private val db: VigilDatabase) {
         db.trackerDao().pruneStale(cutoff)
     }
 
+    /** Wipe the whole tracker list + sighting history (they re-populate as devices
+     *  are re-detected). Keeps learned baseline places. */
+    suspend fun clearAll() = mutex.withLock {
+        db.trackerDao().clearAll()
+        db.sightingDao().clearAll()
+    }
+
     /**
      * Ingest one sighting. Persists it, updates the baseline, and re-evaluates the
      * tracker's risk. Returns the updated row and whether this crossed into ALERTING.

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

@@ -91,6 +91,9 @@ interface TrackerDao {
     // stale, non-approved rows so the table and the UI list don't grow without bound.
     @Query("DELETE FROM trackers WHERE lastSeen < :cutoff AND approved = 0")
     suspend fun pruneStale(cutoff: Long)
+
+    @Query("DELETE FROM trackers")
+    suspend fun clearAll()
 }
 
 @Dao
@@ -103,6 +106,9 @@ interface SightingDao {
 
     @Query("DELETE FROM sightings WHERE timestamp < :cutoff")
     suspend fun prune(cutoff: Long)
+
+    @Query("DELETE FROM sightings")
+    suspend fun clearAll()
 }
 
 @Dao