delete the things that were only ever measuring themselves

lib/ble/ble_engine.dart

@@ -2965,7 +2965,7 @@ class BleEngine {
     // just stores directly if a frame somehow arrives before setup completed.
     final d = _drain;
     if (d != null) {
-      d.onHistoricalRecord(raw, sample);
+      d.onHistoricalRecord(raw, sample, recType);
     } else {
       unawaited(_storeRecord(sample, raw));
     }
@@ -5015,11 +5015,13 @@ class DrainController {
   int get currentBurstHistoricalPacketCount => burstStats.historicalPacketCount;
   String get currentBurstBreakdown => burstStats.breakdownString;
 
-  void onHistoricalRecord(RawRecord raw, Sample? sample) {
+  /// [revision] is the record version byte the ingest path already read off
+  /// the frame (-1 when the frame was too short to have one).
+  void onHistoricalRecord(RawRecord raw, Sample? sample, int revision) {
     records++;
     recordsThisOffload++;
     _lastProgressAt = DateTime.now();
-    burstStats.onHistoricalData(raw.packetType, raw.counter, sample, raw.hex);
+    burstStats.onHistoricalData(raw.packetType, raw.counter, revision);
     if (_buffering) {
       _raws.add(raw);
       _samples.add(sample);
@@ -5364,19 +5366,16 @@ class BurstStats {
     return parts.join(', ');
   }
 
-  void onHistoricalData(
-    int packetType,
-    int counter,
-    Sample? sample,
-    String rawHex,
-  ) {
+  /// [revision] is the record version byte (inner[1]), which the caller has
+  /// already read off the frame. This used to take the record's hex and parse
+  /// the whole thing back into bytes to reach that one byte — a throwaway
+  /// buffer per record, on every record of every offload.
+  void onHistoricalData(int packetType, int counter, int revision) {
     if (packetType != PacketType.historicalData) return;
-    final inner = hexToBytes(rawHex);
-    if (inner.length < 2) {
+    if (revision < 0) {
       _unknownCount++;
       return;
     }
-    final revision = inner[1];
     if (_ordinaryHistoricalRevisions.contains(revision)) {
       _dataPacketCountsByRevision[revision] =
           (_dataPacketCountsByRevision[revision] ?? 0) + 1;

lib/compute/derivation_engine.dart

@@ -3172,8 +3172,6 @@ class DerivationEngine {
       sleepHr: sleepSub.hr,
       sleepRrTsMs: sleepSub.rrTsMs,
       sleepRrMs: sleepSub.rrMs,
-      sleepSpo2Red: sleepSub.spo2Red,
-      sleepSpo2Ir: sleepSub.spo2Ir,
       sleepSkinTemp: sleepSub.skinTemp,
       sleepJson: day.sleepJson,
       hypnoStages: day.hypnoStages,
@@ -3200,7 +3198,6 @@ class DerivationEngine {
       _perDayTimeout,
       label: 'day-bundle ${day.date}',
     );
-    _logSpo2Diagnostics(day, input, bundle);
     // Readiness came back absent for TODAY specifically (not a historical
     // backfill day, which would just be noise) — log why. This ran inside
     // Isolate.run so it couldn't call Firebase itself; it just returned the
@@ -3722,86 +3719,6 @@ class DerivationEngine {
     _log('froze headline readiness ${next.value} for ${next.day}');
   }
 
-  void _logSpo2Diagnostics(
-    PreparedDerivationDay day,
-    DayBundleInput input,
-    Map<String, dynamic> bundle,
-  ) {
-    final red = input.sleepSpo2Red;
-    final ir = input.sleepSpo2Ir;
-    final ts = input.sleepTsSec;
-    if (red.isEmpty || ir.isEmpty || ts.isEmpty) {
-      _log('[spo2-detect] {"day":"${day.date}","status":"no_sleep_spo2"}');
-      return;
-    }
-
-    int minInt(List<int> xs) => xs.reduce((a, b) => a < b ? a : b);
-    int maxInt(List<int> xs) => xs.reduce((a, b) => a > b ? a : b);
-    double meanInt(List<int> xs) =>
-        xs.isEmpty ? 0 : xs.reduce((a, b) => a + b) / xs.length;
-
-    final redNonZero = red.where((v) => v > 0).length;
-    final irNonZero = ir.where((v) => v > 0).length;
-    final spo2 = (bundle['spo2'] as Map?)?.cast<String, dynamic>();
-    final ratios = <double>[
-      for (var i = 0; i < red.length && i < ir.length; i++)
-        if (red[i] > 0 && ir[i] > 0) red[i] / ir[i],
-    ];
-    double? meanDouble(List<double> xs) =>
-        xs.isEmpty ? null : xs.reduce((a, b) => a + b) / xs.length;
-    double? minDouble(List<double> xs) =>
-        xs.isEmpty ? null : xs.reduce((a, b) => a < b ? a : b);
-    double? maxDouble(List<double> xs) =>
-        xs.isEmpty ? null : xs.reduce((a, b) => a > b ? a : b);
-
-    final payload = <String, dynamic>{
-      'day': day.date,
-      'sleep_samples': ts.length,
-      'sleep_span_sec': ts.last - ts.first,
-      'feature_disabled': spo2?['disabled'] == true,
-      'red': <String, dynamic>{
-        'non_zero': redNonZero,
-        'zero': red.length - redNonZero,
-        'coverage': redNonZero / red.length,
-        'unique': red.toSet().length,
-        'min': minInt(red),
-        'max': maxInt(red),
-        'mean': meanInt(red).toStringAsFixed(2),
-        'first10': red.take(10).toList(),
-      },
-      'ir': <String, dynamic>{
-        'non_zero': irNonZero,
-        'zero': ir.length - irNonZero,
-        'coverage': irNonZero / ir.length,
-        'unique': ir.toSet().length,
-        'min': minInt(ir),
-        'max': maxInt(ir),
-        'mean': meanInt(ir).toStringAsFixed(2),
-        'first10': ir.take(10).toList(),
-      },
-      'ratio': <String, dynamic>{
-        'samples': ratios.length,
-        'min': minDouble(ratios)?.toStringAsFixed(6),
-        'max': maxDouble(ratios)?.toStringAsFixed(6),
-        'mean': meanDouble(ratios)?.toStringAsFixed(6),
-        'first10': ratios.take(10).map((v) => v.toStringAsFixed(6)).toList(),
-      },
-      'odi': <String, dynamic>{
-        'disabled': spo2?['disabled'],
-        'note': spo2?['note'],
-        'value': spo2?['odi_per_hour'],
-        'dip_count': spo2?['dip_count'],
-        'signal_coverage': spo2?['signal_coverage'],
-        'trusted_coverage': spo2?['trusted_coverage'],
-        'confidence': spo2?['confidence'],
-        'reject_counts': spo2?['reject_counts'],
-        'severity_counts': spo2?['severity_counts'],
-        'debug': spo2?['debug'],
-      },
-    };
-    _log('[spo2-detect] ${jsonEncode(payload)}');
-  }
-
   /// Skip reasons that describe a TRANSIENT failure of this particular pass
   /// rather than a permanently pathological day. These must never finalize:
   /// finalizing locks the day out of every future pass at this algo version.

lib/compute/onehz_pipeline.dart

@@ -22,6 +22,7 @@
 //         the curve series the UI needs + indexed scalars. Survives jsonEncode.
 
 import 'dart:math' as math;
+import 'dart:typed_data';
 
 import 'package:openstrap_analytics/onehz.dart';
 
@@ -126,8 +127,6 @@ class DayBundleInput {
   final List<int> sleepHr;
   final List<double> sleepRrTsMs;
   final List<double> sleepRrMs;
-  final List<int> sleepSpo2Red;
-  final List<int> sleepSpo2Ir;
   final List<int> sleepSkinTemp;
 
   // ── the SINGLE-SOURCE sleep segmentation (JSON of SleepSegmentation) ──────
@@ -192,8 +191,6 @@ class DayBundleInput {
     required this.sleepHr,
     required this.sleepRrTsMs,
     required this.sleepRrMs,
-    required this.sleepSpo2Red,
-    required this.sleepSpo2Ir,
     required this.sleepSkinTemp,
     required this.sleepJson,
     required this.hypnoStages,
@@ -222,8 +219,6 @@ class DayBundleInput {
     'sleep_hr': sleepHr,
     'sleep_rr_ts_ms': sleepRrTsMs,
     'sleep_rr_ms': sleepRrMs,
-    'sleep_spo2_red': sleepSpo2Red,
-    'sleep_spo2_ir': sleepSpo2Ir,
     'sleep_skin_temp': sleepSkinTemp,
     'sleep_json': sleepJson,
     'hypno_stages': hypnoStages,
@@ -245,9 +240,20 @@ class DayBundleInput {
   static DayBundleInput fromJson(Map<String, dynamic> m) {
     List<int> ints(String k) =>
         ((m[k] as List?) ?? const []).map((e) => (e as num).toInt()).toList();
-    List<double> dbls(String k) => ((m[k] as List?) ?? const [])
-        .map((e) => (e as num).toDouble())
-        .toList();
+    // The substrate packs these as Float64List and the isolate boundary hands
+    // them back typed; unboxing them into a plain List<double> was re-boxing
+    // every element for nothing. Always a COPY, never an alias: on the direct
+    // (synchronous, in-test) path returning the caller's list would share the
+    // substrate's arrays across two repos with nobody enforcing read-only.
+    List<double> dbls(String k) {
+      final v = (m[k] as List?) ?? const [];
+      if (v is List<double>) return Float64List.fromList(v);
+      final out = Float64List(v.length);
+      for (var i = 0; i < v.length; i++) {
+        out[i] = (v[i] as num).toDouble();
+      }
+      return out;
+    }
     List<String> strs(String k) =>
         ((m[k] as List?) ?? const []).map((e) => e.toString()).toList();
     return DayBundleInput(
@@ -260,8 +266,6 @@ class DayBundleInput {
       sleepHr: ints('sleep_hr'),
       sleepRrTsMs: dbls('sleep_rr_ts_ms'),
       sleepRrMs: dbls('sleep_rr_ms'),
-      sleepSpo2Red: ints('sleep_spo2_red'),
-      sleepSpo2Ir: ints('sleep_spo2_ir'),
       sleepSkinTemp: ints('sleep_skin_temp'),
       sleepJson: ((m['sleep_json'] as Map?) ?? const {})
           .cast<String, dynamic>(),
@@ -456,7 +460,6 @@ Map<String, dynamic> deriveDayBundle(Map<String, dynamic> inputJson) {
   const kSpo2Refusal = 'refused: the red and IR channels are one signal — '
       'ir − red is a fixed offset within a session, so any ratio built from '
       'them measures baseline drift, not oxygenation';
-  final odiTs = [for (final t in d.sleepTsSec) t.toDouble()];
   const odi = Metric<RelativeOdiResult>.absent(
     tier: Tier.relative,
     inputs_used: ['spo2_red_raw', 'spo2_ir_raw'],
@@ -1044,7 +1047,7 @@ Map<String, dynamic> deriveDayBundle(Map<String, dynamic> inputJson) {
     'inputs_used': const ['spo2_red_raw', 'spo2_ir_raw'],
     'note': kSpo2Refusal,
     'debug': <String, dynamic>{
-      'sleep_samples': odiTs.length,
+      'sleep_samples': d.sleepTsSec.length,
     },
   };