fix: pack overlapping timeline tasks

apps/focus_flow_flutter/lib/widgets/timeline/task_timeline_card.dart

@@ -126,7 +126,7 @@ class _CardMetrics {
   static const _referenceWidth = 640.0;
   static const _referenceHeight = 88.0;
   static const _freeSlotReferenceHeight = 108.0;
-  static const _minimumScale = 0.62;
+  static const _minimumScale = 0.38;
 
   factory _CardMetrics.fromConstraints(
     BoxConstraints constraints, {

apps/focus_flow_flutter/lib/widgets/timeline/timeline_view.dart

@@ -73,6 +73,7 @@ class _TimelineViewState extends State<TimelineView> {
       minCardHeight: 88,
     );
     final contentHeight = geometry.totalHeight + 24;
+    final placements = _TimelineCardPlacement.pack(widget.cards);
     return LayoutBuilder(
       builder: (context, constraints) {
         _scheduleInitialScroll(geometry, constraints.maxHeight);
@@ -87,26 +88,35 @@ class _TimelineViewState extends State<TimelineView> {
                 TimelineAxis(geometry: geometry),
                 const SizedBox(width: 18),
                 Expanded(
-                  child: Stack(
-                    clipBehavior: Clip.none,
-                    children: [
-                      Positioned.fill(child: TimelineGrid(geometry: geometry)),
-                      for (final card in widget.cards)
-                        Positioned(
-                          top: geometry.yForMinutesSinceMidnight(
-                            card.startMinutes,
+                  child: LayoutBuilder(
+                    builder: (context, cardConstraints) {
+                      final trackWidth = cardConstraints.maxWidth;
+                      return Stack(
+                        clipBehavior: Clip.none,
+                        children: [
+                          Positioned.fill(
+                            child: TimelineGrid(geometry: geometry),
                           ),
-                          left: FocusFlowTokens.cardHorizontalPadding,
-                          right: 0,
-                          height: geometry.heightForDuration(
-                            card.endMinutes - card.startMinutes,
-                          ),
-                          child: TaskTimelineCard(
-                            card: card,
-                            onTap: () => widget.onCardSelected(card),
-                          ),
-                        ),
-                    ],
+                          for (final placement in placements)
+                            Positioned(
+                              top: geometry.yForMinutesSinceMidnight(
+                                placement.card.startMinutes,
+                              ),
+                              left: placement.left(trackWidth),
+                              width: placement.width(trackWidth),
+                              height: geometry.heightForDuration(
+                                placement.card.endMinutes -
+                                    placement.card.startMinutes,
+                              ),
+                              child: TaskTimelineCard(
+                                card: placement.card,
+                                onTap: () =>
+                                    widget.onCardSelected(placement.card),
+                              ),
+                            ),
+                        ],
+                      );
+                    },
                   ),
                 ),
               ],
@@ -171,3 +181,120 @@ class _TimelineViewState extends State<TimelineView> {
     });
   }
 }
+
+class _TimelineCardPlacement {
+  const _TimelineCardPlacement({
+    required this.card,
+    required this.lane,
+    required this.laneCount,
+  });
+
+  static const _laneGap = 8.0;
+
+  final TimelineCardModel card;
+  final int lane;
+  final int laneCount;
+
+  static List<_TimelineCardPlacement> pack(List<TimelineCardModel> cards) {
+    if (cards.isEmpty) {
+      return const [];
+    }
+    final sorted = [...cards]
+      ..sort((a, b) {
+        final startComparison = a.startMinutes.compareTo(b.startMinutes);
+        if (startComparison != 0) {
+          return startComparison;
+        }
+        final endComparison = a.endMinutes.compareTo(b.endMinutes);
+        if (endComparison != 0) {
+          return endComparison;
+        }
+        return a.id.compareTo(b.id);
+      });
+    final placements = <_TimelineCardPlacement>[];
+    var groupStart = 0;
+    var groupEnd = sorted.first.endMinutes;
+    for (var index = 1; index < sorted.length; index += 1) {
+      final card = sorted[index];
+      if (card.startMinutes < groupEnd) {
+        if (card.endMinutes > groupEnd) {
+          groupEnd = card.endMinutes;
+        }
+        continue;
+      }
+      placements.addAll(_packGroup(sorted.sublist(groupStart, index)));
+      groupStart = index;
+      groupEnd = card.endMinutes;
+    }
+    placements.addAll(_packGroup(sorted.sublist(groupStart)));
+    return placements;
+  }
+
+  static List<_TimelineCardPlacement> _packGroup(
+    List<TimelineCardModel> group,
+  ) {
+    final laneEnds = <int>[];
+    final laneByCard = <TimelineCardModel, int>{};
+    for (final card in group) {
+      var assignedLane = -1;
+      for (var lane = 0; lane < laneEnds.length; lane += 1) {
+        if (laneEnds[lane] <= card.startMinutes) {
+          assignedLane = lane;
+          break;
+        }
+      }
+      if (assignedLane == -1) {
+        assignedLane = laneEnds.length;
+        laneEnds.add(card.endMinutes);
+      } else {
+        laneEnds[assignedLane] = card.endMinutes;
+      }
+      laneByCard[card] = assignedLane;
+    }
+    final laneCount = laneEnds.length;
+    return [
+      for (final card in group)
+        _TimelineCardPlacement(
+          card: card,
+          lane: laneByCard[card]!,
+          laneCount: laneCount,
+        ),
+    ];
+  }
+
+  double left(double trackWidth) {
+    final laneWidth = _laneWidth(trackWidth);
+    final laneGap = _laneGapForWidth(trackWidth);
+    return FocusFlowTokens.cardHorizontalPadding + lane * (laneWidth + laneGap);
+  }
+
+  double width(double trackWidth) {
+    return _laneWidth(trackWidth);
+  }
+
+  double _availableWidth(double trackWidth) {
+    final availableWidth = trackWidth - FocusFlowTokens.cardHorizontalPadding;
+    if (availableWidth < 0) {
+      return 0;
+    }
+    return availableWidth;
+  }
+
+  double _laneWidth(double trackWidth) {
+    final availableWidth = _availableWidth(trackWidth);
+    final laneGap = _laneGapForWidth(trackWidth);
+    return (availableWidth - laneGap * (laneCount - 1)) / laneCount;
+  }
+
+  double _laneGapForWidth(double trackWidth) {
+    if (laneCount == 1) {
+      return 0;
+    }
+    final availableWidth = _availableWidth(trackWidth);
+    final totalGap = _laneGap * (laneCount - 1);
+    if (availableWidth <= totalGap) {
+      return 0;
+    }
+    return _laneGap;
+  }
+}

apps/focus_flow_flutter/test/widget_test.dart

@@ -159,6 +159,57 @@ void main() {
     },
   );
 
+  testWidgets('timeline reuses empty overlap lanes for chained tasks', (
+    tester,
+  ) async {
+    await _pumpConstrainedWidget(
+      tester,
+      size: const Size(680, 520),
+      child: TimelineView(
+        cards: [
+          _timelineCard(
+            id: 'left-first',
+            title: 'Left first',
+            startMinutes: 9 * 60,
+            endMinutes: 10 * 60,
+          ),
+          _timelineCard(
+            id: 'right-middle',
+            title: 'Right middle',
+            startMinutes: 9 * 60 + 30,
+            endMinutes: 10 * 60 + 30,
+          ),
+          _timelineCard(
+            id: 'left-reused',
+            title: 'Left reused',
+            startMinutes: 10 * 60,
+            endMinutes: 11 * 60,
+          ),
+        ],
+        range: TodayScreenData.defaultRange,
+        now: () => DateTime(2026, 6, 30, 9, 30),
+        onCardSelected: (_) {},
+      ),
+    );
+
+    expect(tester.takeException(), isNull);
+
+    final leftFirst = tester.getRect(find.byKey(const ValueKey('left-first')));
+    final rightMiddle = tester.getRect(
+      find.byKey(const ValueKey('right-middle')),
+    );
+    final leftReused = tester.getRect(
+      find.byKey(const ValueKey('left-reused')),
+    );
+
+    expect(rightMiddle.left, greaterThan(leftFirst.left));
+    expect(leftReused.left, closeTo(leftFirst.left, 1));
+    expect(leftFirst.width, closeTo(rightMiddle.width, 1));
+    expect(leftReused.width, closeTo(leftFirst.width, 1));
+    expect(leftFirst.right, lessThan(rightMiddle.left));
+    expect(leftReused.right, lessThan(rightMiddle.left));
+  });
+
   testWidgets('top bar controls scale inside a compact header width', (
     tester,
   ) async {
@@ -338,6 +389,8 @@ TimelineCardModel _timelineCard({
   required String title,
   String subtitle = '30 min',
   String timeText = '6:00 PM - 6:30 PM',
+  int startMinutes = 18 * 60,
+  int endMinutes = 18 * 60 + 30,
   TaskVisualKind visualKind = TaskVisualKind.flexible,
   bool showsQuickActions = true,
 }) {
@@ -347,8 +400,8 @@ TimelineCardModel _timelineCard({
     typeLabel: 'Flexible',
     subtitle: subtitle,
     timeText: timeText,
-    startMinutes: 18 * 60,
-    endMinutes: 18 * 60 + 30,
+    startMinutes: startMinutes,
+    endMinutes: endMinutes,
     visualKind: visualKind,
     rewardIconToken: TimelineRewardIconToken.medium,
     difficultyIconToken: TimelineDifficultyIconToken.medium,