Health Connect: Fix partial sleep sessions not being replaced by full data

Sleep sessions that grow over time (partial data synced mid-sleep, full
data available after waking) were permanently stuck as partial records
in Health Connect. The sync cursor advanced past the session's start
after the first sync, so the full session was never re-processed.

Fix with two mechanisms:
- Set clientRecordId per sleep session (deterministic from device +
  start hour) with clientRecordVersion = stage count, enabling HC's
  native upsert: re-inserting the same session replaces partial data
  with the full record.
- Hold the sync cursor behind sessions that ended less than 6 hours
  ago (likely still in-progress), so they get re-processed on the
  next sync with more complete data.

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/util/healthconnect/syncers/SleepSyncer.kt

@@ -29,9 +29,12 @@ import nodomain.freeyourgadget.gadgetbridge.util.healthconnect.HealthConnectUtil
 import org.slf4j.LoggerFactory
 import java.time.Instant
 import java.time.ZoneId
+import java.time.temporal.ChronoUnit
 
 private val LOG = LoggerFactory.getLogger("SleepSyncer")
 
+private const val IN_PROGRESS_THRESHOLD_HOURS = 6L
+
 internal object SleepSyncer : ContextualActivitySampleSyncer {
 
     override suspend fun sync(
@@ -101,7 +104,22 @@ internal object SleepSyncer : ContextualActivitySampleSyncer {
         LOG.info("Attempting to insert ${sleepSessionRecordList.size} SleepSessionRecord(s) for device '$deviceName' for slice $sliceStartBoundary to $sliceEndBoundary.")
         HealthConnectUtils.insertRecords(sleepSessionRecordList, healthConnectClient)
         LOG.info("Successfully inserted SleepSessionRecord(s) for device '$deviceName' for slice $sliceStartBoundary to $sliceEndBoundary.")
-        val latestTs = sleepSessionRecordList.maxOfOrNull { it.endTime }
+
+        val now = Instant.now()
+        var latestTs: Instant? = null
+        for (record in sleepSessionRecordList) {
+            val sessionEnd = record.endTime
+            val sessionStart = record.startTime
+            val effectiveTs = if (sessionEnd.isAfter(now.minus(IN_PROGRESS_THRESHOLD_HOURS, ChronoUnit.HOURS))) {
+                LOG.info("Sleep session ending at $sessionEnd may still be in progress — holding cursor at $sessionStart for re-processing.")
+                sessionStart.minusSeconds(1)
+            } else {
+                sessionEnd
+            }
+            if (latestTs == null || effectiveTs.isAfter(latestTs)) {
+                latestTs = effectiveTs
+            }
+        }
         return SyncerStatistics(recordsSynced = sleepSessionRecordList.size, recordsSkipped = skippedCount, recordType = "Sleep", latestRecordTimestamp = latestTs)
     }
 
@@ -180,6 +198,15 @@ internal object SleepSyncer : ContextualActivitySampleSyncer {
 
         LOG.info("Prepared SleepSessionRecord for device '$deviceName' (Session: $recordFinalStartTime to $recordFinalEndTime). Stages: ${stages.size}")
 
+        val startHourEpoch = recordFinalStartTime.epochSecond / 3600 * 3600
+        val clientRecordId = "gb-sleep-${metadata.device?.manufacturer ?: "unknown"}-${metadata.device?.model ?: "unknown"}-$startHourEpoch"
+        val sessionMetadata = Metadata.autoRecorded(
+            clientRecordId = clientRecordId,
+            clientRecordVersion = stages.size.toLong(),
+            device = metadata.device!!
+        )
+        LOG.info("Sleep session clientRecordId=$clientRecordId, clientRecordVersion=${stages.size}")
+
         return SleepSessionRecord(
             startTime = recordFinalStartTime,
             startZoneOffset = offset.rules.getOffset(recordFinalStartTime),
@@ -188,7 +215,7 @@ internal object SleepSyncer : ContextualActivitySampleSyncer {
             title = context.getString(nodomain.freeyourgadget.gadgetbridge.R.string.health_connect_sleep_session_title, deviceName),
             notes = context.getString(nodomain.freeyourgadget.gadgetbridge.R.string.health_connect_sleep_session_notes, deviceName),
             stages = stages,
-            metadata = metadata
+            metadata = sessionMetadata
         )
     }