feat(stats): drop seek markers from session timeline

Seek-forward / seek-backward events cluttered sessions with lots of
rewinds — a single episode could show dozens of << and >> icons
overlapping the card and pause markers. Stop requesting them from the
backend, drop them from buildSessionChartEvents, remove the seek
variant from SessionChartMarker, and strip the matching ReferenceLines,
overlay marker, popover branch, and legend entry from SessionDetail.

stats/src/components/sessions/SessionDetail.tsx

@@ -125,14 +125,13 @@ export function SessionDetail({ session }: SessionDetailProps) {
   const knownWordsMap = buildKnownWordsLookup(knownWordsTimeline);
   const hasKnownWords = knownWordsMap.size > 0;
 
-  const { cardEvents, seekEvents, yomitanLookupEvents, pauseRegions, markers } =
+  const { cardEvents, yomitanLookupEvents, pauseRegions, markers } =
     buildSessionChartEvents(events);
   const lookupRate = buildLookupRateDisplay(
     session.yomitanLookupCount,
     getSessionDisplayWordCount(session),
   );
   const pauseCount = events.filter((e) => e.eventType === EventType.PAUSE_START).length;
-  const seekCount = seekEvents.length;
   const cardEventCount = cardEvents.length;
   const activeMarkerKey = resolveActiveSessionMarkerKey(hoveredMarkerKey, pinnedMarkerKey);
   const activeMarker = useMemo<SessionChartMarker | null>(
@@ -230,7 +229,6 @@ export function SessionDetail({ session }: SessionDetailProps) {
         sorted={sorted}
         knownWordsMap={knownWordsMap}
         cardEvents={cardEvents}
-        seekEvents={seekEvents}
         yomitanLookupEvents={yomitanLookupEvents}
         pauseRegions={pauseRegions}
         markers={markers}
@@ -242,7 +240,6 @@ export function SessionDetail({ session }: SessionDetailProps) {
         loadingNoteIds={loadingNoteIds}
         onOpenNote={handleOpenNote}
         pauseCount={pauseCount}
-        seekCount={seekCount}
         cardEventCount={cardEventCount}
         lookupRate={lookupRate}
         session={session}
@@ -254,7 +251,6 @@ export function SessionDetail({ session }: SessionDetailProps) {
     <FallbackView
       sorted={sorted}
       cardEvents={cardEvents}
-      seekEvents={seekEvents}
       yomitanLookupEvents={yomitanLookupEvents}
       pauseRegions={pauseRegions}
       markers={markers}
@@ -266,7 +262,6 @@ export function SessionDetail({ session }: SessionDetailProps) {
       loadingNoteIds={loadingNoteIds}
       onOpenNote={handleOpenNote}
       pauseCount={pauseCount}
-      seekCount={seekCount}
       cardEventCount={cardEventCount}
       lookupRate={lookupRate}
       session={session}
@@ -280,7 +275,6 @@ function RatioView({
   sorted,
   knownWordsMap,
   cardEvents,
-  seekEvents,
   yomitanLookupEvents,
   pauseRegions,
   markers,
@@ -292,7 +286,6 @@ function RatioView({
   loadingNoteIds,
   onOpenNote,
   pauseCount,
-  seekCount,
   cardEventCount,
   lookupRate,
   session,
@@ -300,7 +293,6 @@ function RatioView({
   sorted: TimelineEntry[];
   knownWordsMap: Map<number, number>;
   cardEvents: SessionEvent[];
-  seekEvents: SessionEvent[];
   yomitanLookupEvents: SessionEvent[];
   pauseRegions: Array<{ startMs: number; endMs: number }>;
   markers: SessionChartMarker[];
@@ -312,7 +304,6 @@ function RatioView({
   loadingNoteIds: Set<number>;
   onOpenNote: (noteId: number) => void;
   pauseCount: number;
-  seekCount: number;
   cardEventCount: number;
   lookupRate: ReturnType<typeof buildLookupRateDisplay>;
   session: SessionSummary;
@@ -450,22 +441,6 @@ function RatioView({
               />
             ))}
 
-            {seekEvents.map((e, i) => {
-              const isBackward = e.eventType === EventType.SEEK_BACKWARD;
-              const stroke = isBackward ? '#f5bde6' : '#8bd5ca';
-              return (
-                <ReferenceLine
-                  key={`seek-${i}`}
-                  yAxisId="pct"
-                  x={e.tsMs}
-                  stroke={stroke}
-                  strokeWidth={1.5}
-                  strokeOpacity={0.75}
-                  strokeDasharray="4 3"
-                />
-              );
-            })}
-
             {/* Yomitan lookup markers */}
             {yomitanLookupEvents.map((e, i) => (
               <ReferenceLine
@@ -549,7 +524,6 @@ function RatioView({
       <StatsBar
         hasKnownWords
         pauseCount={pauseCount}
-        seekCount={seekCount}
         cardEventCount={cardEventCount}
         session={session}
         lookupRate={lookupRate}
@@ -563,7 +537,6 @@ function RatioView({
 function FallbackView({
   sorted,
   cardEvents,
-  seekEvents,
   yomitanLookupEvents,
   pauseRegions,
   markers,
@@ -575,14 +548,12 @@ function FallbackView({
   loadingNoteIds,
   onOpenNote,
   pauseCount,
-  seekCount,
   cardEventCount,
   lookupRate,
   session,
 }: {
   sorted: TimelineEntry[];
   cardEvents: SessionEvent[];
-  seekEvents: SessionEvent[];
   yomitanLookupEvents: SessionEvent[];
   pauseRegions: Array<{ startMs: number; endMs: number }>;
   markers: SessionChartMarker[];
@@ -594,7 +565,6 @@ function FallbackView({
   loadingNoteIds: Set<number>;
   onOpenNote: (noteId: number) => void;
   pauseCount: number;
-  seekCount: number;
   cardEventCount: number;
   lookupRate: ReturnType<typeof buildLookupRateDisplay>;
   session: SessionSummary;
@@ -680,20 +650,6 @@ function FallbackView({
                 strokeOpacity={0.8}
               />
             ))}
-            {seekEvents.map((e, i) => {
-              const isBackward = e.eventType === EventType.SEEK_BACKWARD;
-              const stroke = isBackward ? '#f5bde6' : '#8bd5ca';
-              return (
-                <ReferenceLine
-                  key={`seek-${i}`}
-                  x={e.tsMs}
-                  stroke={stroke}
-                  strokeWidth={1.5}
-                  strokeOpacity={0.75}
-                  strokeDasharray="4 3"
-                />
-              );
-            })}
             {yomitanLookupEvents.map((e, i) => (
               <ReferenceLine
                 key={`yomitan-${i}`}
@@ -735,7 +691,6 @@ function FallbackView({
       <StatsBar
         hasKnownWords={false}
         pauseCount={pauseCount}
-        seekCount={seekCount}
         cardEventCount={cardEventCount}
         session={session}
         lookupRate={lookupRate}
@@ -749,14 +704,12 @@ function FallbackView({
 function StatsBar({
   hasKnownWords,
   pauseCount,
-  seekCount,
   cardEventCount,
   session,
   lookupRate,
 }: {
   hasKnownWords: boolean;
   pauseCount: number;
-  seekCount: number;
   cardEventCount: number;
   session: SessionSummary;
   lookupRate: ReturnType<typeof buildLookupRateDisplay>;
@@ -791,12 +744,7 @@ function StatsBar({
           {pauseCount !== 1 ? 's' : ''}
         </span>
       )}
-      {seekCount > 0 && (
-        <span className="text-ctp-overlay2">
-          <span className="text-ctp-teal">{seekCount}</span> seek{seekCount !== 1 ? 's' : ''}
-        </span>
-      )}
-      {(pauseCount > 0 || seekCount > 0) && <span className="text-ctp-surface2">|</span>}
+      {pauseCount > 0 && <span className="text-ctp-surface2">|</span>}
 
       {/* Group 3: Learning events */}
       <span className="flex items-center gap-1.5">

stats/src/components/sessions/SessionEventOverlay.tsx

@@ -33,8 +33,6 @@ function markerLabel(marker: SessionChartMarker): string {
   switch (marker.kind) {
     case 'pause':
       return '||';
-    case 'seek':
-      return marker.direction === 'backward' ? '<<' : '>>';
     case 'card':
       return '\u26CF';
   }
@@ -44,10 +42,6 @@ function markerColors(marker: SessionChartMarker): { border: string; bg: string;
   switch (marker.kind) {
     case 'pause':
       return { border: '#f5a97f', bg: 'rgba(245,169,127,0.16)', text: '#f5a97f' };
-    case 'seek':
-      return marker.direction === 'backward'
-        ? { border: '#f5bde6', bg: 'rgba(245,189,230,0.16)', text: '#f5bde6' }
-        : { border: '#8bd5ca', bg: 'rgba(139,213,202,0.16)', text: '#8bd5ca' };
     case 'card':
       return { border: '#a6da95', bg: 'rgba(166,218,149,0.16)', text: '#a6da95' };
   }

stats/src/components/sessions/SessionEventPopover.test.tsx

@@ -41,35 +41,6 @@ test('SessionEventPopover renders formatted card-mine details with fetched note
   assert.match(markup, /Open in Anki/);
 });
 
-test('SessionEventPopover renders seek metadata compactly', () => {
-  const marker: SessionChartMarker = {
-    key: 'seek-3000',
-    kind: 'seek',
-    anchorTsMs: 3_000,
-    eventTsMs: 3_000,
-    direction: 'backward',
-    fromMs: 5_000,
-    toMs: 1_500,
-  };
-
-  const markup = renderToStaticMarkup(
-    <SessionEventPopover
-      marker={marker}
-      noteInfos={new Map()}
-      loading={false}
-      pinned={false}
-      onTogglePinned={() => {}}
-      onClose={() => {}}
-      onOpenNote={() => {}}
-    />,
-  );
-
-  assert.match(markup, /Seek backward/);
-  assert.match(markup, /5\.0s/);
-  assert.match(markup, /1\.5s/);
-  assert.match(markup, /3\.5s/);
-});
-
 test('SessionEventPopover renders a cleaner fallback when AnkiConnect provides no preview fields', () => {
   const marker: SessionChartMarker = {
     key: 'card-9000',

stats/src/components/sessions/SessionEventPopover.tsx

@@ -31,18 +31,12 @@ export function SessionEventPopover({
   onClose,
   onOpenNote,
 }: SessionEventPopoverProps) {
-  const seekDurationLabel =
-    marker.kind === 'seek' && marker.fromMs !== null && marker.toMs !== null
-      ? formatEventSeconds(Math.abs(marker.toMs - marker.fromMs))?.replace(/\.0s$/, 's')
-      : null;
-
   return (
     <div className="relative z-50 w-64 rounded-xl border border-ctp-surface2 bg-ctp-surface0/95 p-3 shadow-2xl shadow-black/30 backdrop-blur-sm">
       <div className="mb-2 flex items-start justify-between gap-3">
         <div>
           <div className="text-xs font-semibold text-ctp-text">
             {marker.kind === 'pause' && 'Paused'}
-            {marker.kind === 'seek' && `Seek ${marker.direction}`}
             {marker.kind === 'card' && 'Card mined'}
           </div>
           <div className="text-[10px] text-ctp-overlay1">{formatEventTime(marker.eventTsMs)}</div>
@@ -72,7 +66,6 @@ export function SessionEventPopover({
           ) : null}
           <div className="text-sm">
             {marker.kind === 'pause' && '||'}
-            {marker.kind === 'seek' && (marker.direction === 'backward' ? '<<' : '>>')}
             {marker.kind === 'card' && '\u26CF'}
           </div>
         </div>
@@ -84,19 +77,6 @@ export function SessionEventPopover({
         </div>
       )}
 
-      {marker.kind === 'seek' && (
-        <div className="space-y-1 text-xs text-ctp-subtext0">
-          <div>
-            From{' '}
-            <span className="text-ctp-teal">{formatEventSeconds(marker.fromMs) ?? '\u2014'}</span>{' '}
-            to <span className="text-ctp-teal">{formatEventSeconds(marker.toMs) ?? '\u2014'}</span>
-          </div>
-          <div>
-            Length <span className="text-ctp-peach">{seekDurationLabel ?? '\u2014'}</span>
-          </div>
-        </div>
-      )}
-
       {marker.kind === 'card' && (
         <div className="space-y-2">
           <div className="text-xs text-ctp-cards-mined">