fix(history): retain 200 trip summaries

Author: malys

CHANGELOG.md

@@ -23,7 +23,8 @@ All notable changes to this project are documented here. Format follows
 - **Trip history can be pruned without bypassing its atomic persistence boundary.**
   `EnergyTripHistoryStore` can remove one start-time-identified trip or replace the history with
   a valid empty v2 envelope; both operations preserve the same unique-temp-file rewrite used by
-  appends, so a UI never deletes the only valid file before its replacement exists.
+  appends, so a UI never deletes the only valid file before its replacement exists. The default
+  summary bound is 200 trips; the existing byte ceiling still drops old sample tracks first.
 
 - **A public post-AAOS 9 capacity signal can be tested without becoming product data.**
   `EV_CURRENT_BATTERY_CAPACITY` describes real-time usable capacity rather than the pack's nominal

lib/src/main/java/com/evsuite/hardware/telemetry/EnergyTripHistoryStore.kt

@@ -42,7 +42,7 @@ data class TripHistoryFile(
  */
 class EnergyTripHistoryStore(
     private val target: File,
-    private val maxTrips: Int = 50,
+    private val maxTrips: Int = 200,
     private val maxBytes: Int = 512 * 1024,
     private val gson: Gson = Gson(),
 ) {

lib/src/test/java/com/evsuite/hardware/telemetry/TripHistoryStoreTest.kt

@@ -141,6 +141,18 @@ class TripHistoryStoreTest {
         assertEquals(30, store.read().size)
     }
 
+    @Test fun `the default history retains two hundred summaries newest first`() {
+        val directory = tempDirectory()
+        val store = EnergyTripHistoryStore(File(directory, "trips.json"))
+
+        repeat(201) { trip -> assertTrue(store.append(summary(trip.toLong()))) }
+
+        val starts = store.readSummaries().map { it.startedAtMs }
+        assertEquals(200, starts.size)
+        assertEquals(200L, starts.first())
+        assertEquals(1L, starts.last())
+    }
+
     @Test fun `a four hour trip is decimated rather than truncated`() {
         val track = TripSampleTrack(startIntervalMs = 5_000L, maxSamples = 64)
         // Four hours at 1 Hz: 14 400 reads, of which the track would keep 2 880 at 5 s.