feat(stats): add Reading Speed and Cards/Hour efficiency charts to Trend

- Add cardsPerHour and readingSpeed series to TrendsDashboardQueryResult and TrendsDashboardData
- Reorganize Trends tab into Activity, Cumulative Totals, Efficiency, Patterns, and Library sections
- Disambiguate per-period vs cumulative chart titles
- Label Activity section header with current groupBy period

changes/stats-updates.md

@@ -5,4 +5,5 @@ area: stats
 - Improved Stats mining from Search and vocabulary examples: empty `ankiConnect.deck` can use Yomitan's mining deck, sentence cards are created before slow media generation finishes, stored/requested secondary subtitles are preserved before falling back to sidecar files or temporary alass-retimed English sidecars for sentence Selection Text, invalid stored timings are blocked before FFmpeg runs, future out-of-order subtitle timing pairs are skipped until valid timings arrive, and partial media failures are shown.
 - Fixed Stats mining field/audio behavior so sentence clips update `SentenceAudio`, word audio uses the configured Yomitan sources, English subtitle text is not written onto word cards, and secondary subtitle auto-selection prefers regular English tracks over Signs/Songs tracks.
 - Improved vocabulary review with remembered Hide Known/Hide Kana filters, duplicate-collapsed exclusions across token variants, and Related Seen Words matching based on shared readings or kanji.
+- Reorganized the Stats Trends tab into clearer Activity, Cumulative Totals, Efficiency, Patterns, and Library sections, disambiguated per-period vs cumulative charts, and added Reading Speed (words/min) and Cards/Hour efficiency charts.
 - Improved Stats browsing reliability by remembering library card size, retrying stored cover art without extra AniList lookups, preserving PNG/WebP cover MIME types, honoring custom AnkiConnect URLs for Browse, showing progress during session deletes, and making session deletes refresh faster.

docs-site/immersion-tracking.md

@@ -54,7 +54,7 @@ When YouTube channel metadata is available, the Library tab groups videos by cre
 
 #### Trends
 
-Watch time, sessions, words seen, and per-anime progress/pattern charts with configurable date ranges and grouping.
+Grouped into Activity (per-day/month watch time, cards, words, sessions), Cumulative Totals (running totals incl. new words learned and episodes), Efficiency (reading speed, cards/hour, lookups per 100 words), Patterns (watch time by day of week and hour), and per-anime Library charts — all with configurable date ranges and grouping.
 
 ![Stats Trends](/screenshots/stats-trends.png)
 

src/core/services/immersion-tracker/__tests__/query.test.ts

@@ -761,6 +761,10 @@ test('getTrendsDashboard returns chart-ready aggregated series', () => {
     assert.equal(dashboard.progress.watchTime[1]?.value, 75);
     assert.equal(dashboard.progress.lookups[1]?.value, 18);
     assert.equal(dashboard.ratios.lookupsPerHundred[0]?.value, +((8 / 120) * 100).toFixed(1));
+    assert.equal(dashboard.ratios.cardsPerHour[0]?.value, +(2 / (30 / 60)).toFixed(1));
+    assert.equal(dashboard.ratios.cardsPerHour[1]?.value, +(3 / (45 / 60)).toFixed(1));
+    assert.equal(dashboard.ratios.readingSpeed[0]?.value, +(120 / 30).toFixed(1));
+    assert.equal(dashboard.ratios.readingSpeed[1]?.value, +(140 / 45).toFixed(1));
     assert.equal(dashboard.librarySummary[0]?.title, 'Trend Dashboard Anime');
     assert.equal(dashboard.animeCumulative.watchTime[1]?.value, 75);
     assert.equal(

src/core/services/immersion-tracker/query-trends.ts

@@ -74,6 +74,8 @@ export interface TrendsDashboardQueryResult {
   };
   ratios: {
     lookupsPerHundred: TrendChartPoint[];
+    cardsPerHour: TrendChartPoint[];
+    readingSpeed: TrendChartPoint[];
   };
   animeCumulative: {
     watchTime: TrendPerAnimePoint[];
@@ -225,6 +227,26 @@ function buildAggregatedTrendRows(rollups: ImmersionSessionRollupRow[]) {
     }));
 }
 
+function buildEfficiencyRates(rows: ReturnType<typeof buildAggregatedTrendRows>): {
+  cardsPerHour: TrendChartPoint[];
+  readingSpeed: TrendChartPoint[];
+} {
+  const cardsPerHour: TrendChartPoint[] = [];
+  const readingSpeed: TrendChartPoint[] = [];
+  for (const row of rows) {
+    const hours = row.activeMin / 60;
+    cardsPerHour.push({
+      label: row.label,
+      value: hours > 0 ? +(row.cards / hours).toFixed(1) : 0,
+    });
+    readingSpeed.push({
+      label: row.label,
+      value: row.activeMin > 0 ? +(row.words / row.activeMin).toFixed(1) : 0,
+    });
+  }
+  return { cardsPerHour, readingSpeed };
+}
+
 function buildWatchTimeByDayOfWeek(sessions: TrendSessionMetricRow[]): TrendChartPoint[] {
   const totals = new Array(7).fill(0);
   for (const session of sessions) {
@@ -675,6 +697,7 @@ export function getTrendsDashboard(
   );
 
   const aggregatedRows = buildAggregatedTrendRows(chartRollups);
+  const efficiency = buildEfficiencyRates(aggregatedRows);
   const activity = {
     watchTime: aggregatedRows.map((row) => ({ label: row.label, value: row.activeMin })),
     cards: aggregatedRows.map((row) => ({ label: row.label, value: row.cards })),
@@ -724,6 +747,8 @@ export function getTrendsDashboard(
     },
     ratios: {
       lookupsPerHundred: buildLookupsPerHundredWords(sessions, groupBy),
+      cardsPerHour: efficiency.cardsPerHour,
+      readingSpeed: efficiency.readingSpeed,
     },
     animeCumulative: {
       watchTime: buildCumulativePerAnime(animePerDay.watchTime),

stats/src/components/trends/TrendsTab.tsx

@@ -148,7 +148,7 @@ export function TrendsTab() {
         onGroupByChange={setGroupBy}
       />
       <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
-        <SectionHeader>Activity</SectionHeader>
+        <SectionHeader>Activity (per {groupBy === 'month' ? 'month' : 'day'})</SectionHeader>
         <TrendChart
           title="Watch Time (min)"
           data={data.activity.watchTime}
@@ -163,6 +163,72 @@ export function TrendsTab() {
         />
         <TrendChart title="Words Seen" data={data.activity.words} color="#8bd5ca" type="bar" />
         <TrendChart title="Sessions" data={data.activity.sessions} color="#b7bdf8" type="bar" />
+
+        <SectionHeader>Cumulative Totals</SectionHeader>
+        <TrendChart
+          title="Watch Time, cumulative (min)"
+          data={data.progress.watchTime}
+          color="#8aadf4"
+          type="line"
+        />
+        <TrendChart
+          title="Words Seen (cumulative)"
+          data={data.progress.words}
+          color="#8bd5ca"
+          type="line"
+        />
+        <TrendChart
+          title="New Words Learned (cumulative)"
+          data={data.progress.newWords}
+          color="#c6a0f6"
+          type="line"
+        />
+        <TrendChart
+          title="Cards Mined (cumulative)"
+          data={data.progress.cards}
+          color={cardsMinedColor}
+          type="line"
+        />
+        <TrendChart
+          title="Episodes Watched (cumulative)"
+          data={data.progress.episodes}
+          color="#91d7e3"
+          type="line"
+        />
+        <TrendChart
+          title="Sessions (cumulative)"
+          data={data.progress.sessions}
+          color="#b7bdf8"
+          type="line"
+        />
+        <TrendChart
+          title="Lookups (cumulative)"
+          data={data.progress.lookups}
+          color="#f5bde6"
+          type="line"
+        />
+
+        <SectionHeader>Efficiency</SectionHeader>
+        <TrendChart
+          title="Reading Speed (words / min)"
+          data={data.ratios.readingSpeed}
+          color="#a6da95"
+          type="line"
+        />
+        <TrendChart
+          title="Cards / Hour"
+          data={data.ratios.cardsPerHour}
+          color={cardsMinedColor}
+          type="line"
+        />
+        <TrendChart
+          title="Lookups / 100 Words"
+          data={data.ratios.lookupsPerHundred}
+          color="#f5a97f"
+          type="line"
+        />
+
+        <SectionHeader>Patterns</SectionHeader>
         <TrendChart
           title="Watch Time by Day of Week (min)"
           data={data.patterns.watchTimeByDayOfWeek}
@@ -176,41 +242,6 @@ export function TrendsTab() {
           type="bar"
         />
 
-        <SectionHeader>Period Trends</SectionHeader>
-        <TrendChart
-          title="Watch Time (min)"
-          data={data.progress.watchTime}
-          color="#8aadf4"
-          type="line"
-        />
-        <TrendChart title="Sessions" data={data.progress.sessions} color="#b7bdf8" type="line" />
-        <TrendChart title="Words Seen" data={data.progress.words} color="#8bd5ca" type="line" />
-        <TrendChart
-          title="New Words Seen"
-          data={data.progress.newWords}
-          color="#c6a0f6"
-          type="line"
-        />
-        <TrendChart
-          title="Cards Mined"
-          data={data.progress.cards}
-          color={cardsMinedColor}
-          type="line"
-        />
-        <TrendChart
-          title="Episodes Watched"
-          data={data.progress.episodes}
-          color="#91d7e3"
-          type="line"
-        />
-        <TrendChart title="Lookups" data={data.progress.lookups} color="#f5bde6" type="line" />
-        <TrendChart
-          title="Lookups / 100 Words"
-          data={data.ratios.lookupsPerHundred}
-          color="#f5a97f"
-          type="line"
-        />
-
         <SectionHeader>Library — Cumulative</SectionHeader>
         <AnimeVisibilityFilter
           animeTitles={animeTitles}

stats/src/types/stats.ts

@@ -349,6 +349,8 @@ export interface TrendsDashboardData {
   };
   ratios: {
     lookupsPerHundred: TrendChartPoint[];
+    cardsPerHour: TrendChartPoint[];
+    readingSpeed: TrendChartPoint[];
   };
   librarySummary: LibrarySummaryRow[];
   animeCumulative: {