Merge S1/S2 sleep average + mood saturation into release/v1.19.1

S1: add an average-per-night sleep card as a third peer beside debt and
chronotype, computed by a shared helper over the same scorable-night set
so the three cannot disagree; grid widens to three columns. S2: restore
full saturation on the two missed mood surfaces (calendar heatmap and the
time-of-day chart), keeping the quiet tint only for no-data cells.

src/components/charts/mood-heatmap.tsx

@@ -271,7 +271,10 @@ export function MoodHeatmap({
                 height={cellSize}
                 rx={2}
                 fill={cell.color}
-                fillOpacity={cell.cell ? 0.55 : 1}
+                // v1.19.1 — populated days render at full saturation so the
+                // mood band reads clearly; only the no-entry cells stay the
+                // quiet `--secondary` empty-state tint.
+                fillOpacity={1}
                 className="cursor-pointer"
                 onPointerEnter={(e) => {
                   if (e.pointerType === "touch") return;
@@ -331,7 +334,7 @@ export function MoodHeatmap({
           <span key={label} className="flex items-center gap-1">
             <div
               className="h-3 w-3 rounded-sm"
-              style={{ backgroundColor: color, opacity: 0.55 }}
+              style={{ backgroundColor: color }}
             />
             {label}
           </span>

src/components/insights/mood/mood-time-of-day-chart.tsx

@@ -84,10 +84,9 @@ export function MoodTimeOfDayChart({
             data={data}
             margin={{ top: 8, right: 12, bottom: 8, left: 0 }}
           >
-            {/* Muted chart language — same treatment as the weekday/distribution
-                siblings: `--muted-foreground` axis ticks, a quiet comment-grey
-                target guide, and 0.55 bar fill so the level hues inform without
-                shouting. */}
+            {/* Quiet chart language — `--muted-foreground` axis ticks and a
+                comment-grey target guide. The bars themselves render at full
+                saturation (v1.19.1) so the mood level hues read clearly. */}
             <XAxis
               dataKey="label"
               tick={{ fontSize: 11, fill: "var(--muted-foreground)" }}
@@ -130,7 +129,10 @@ export function MoodTimeOfDayChart({
                 ];
               }}
             />
-            <Bar dataKey="value" radius={[3, 3, 0, 0]} fillOpacity={0.55}>
+            {/* v1.19.1 — populated buckets render at full saturation so the
+                level hues read clearly; only the no-data buckets keep the quiet
+                `--secondary` empty-state tint. */}
+            <Bar dataKey="value" radius={[3, 3, 0, 0]}>
               {data.map((row) => (
                 <Cell
                   key={row.bucket}
@@ -139,6 +141,7 @@ export function MoodTimeOfDayChart({
                       ? "var(--secondary)"
                       : colorForScore(row.avgScore)
                   }
+                  fillOpacity={row.avgScore == null ? 0.55 : 1}
                 />
               ))}
             </Bar>

src/components/insights/sleep/__tests__/chronotype-section.test.tsx

@@ -50,6 +50,12 @@ const READY_DTO: SleepRhythmDto = {
     workNightsCounted: 14,
     freeNightsUntilReady: 0,
   },
+  averagePerNight: {
+    state: "ready",
+    averageMinutes: 420,
+    nightsCounted: 10,
+    nightsUntilReady: 0,
+  },
 };
 
 beforeEach(() => {

src/components/insights/sleep/__tests__/sleep-rhythm-section.test.tsx

@@ -58,6 +58,12 @@ const READY_DTO: SleepRhythmDto = {
     workNightsCounted: 14,
     freeNightsUntilReady: 0,
   },
+  averagePerNight: {
+    state: "ready",
+    averageMinutes: 420,
+    nightsCounted: 5,
+    nightsUntilReady: 0,
+  },
 };
 
 beforeEach(() => {

src/components/insights/sleep/average-sleep-card.tsx

@@ -0,0 +1,83 @@
+"use client";
+
+import { BedDouble } from "lucide-react";
+
+import { useTranslations } from "@/lib/i18n/context";
+import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
+import { LearningGate } from "@/components/ui/learning-gate";
+import type { AverageSleepDto } from "./use-sleep-rhythm";
+
+/** Whole hours + minutes from a minute total, for the headline figure. */
+function hoursMinutes(totalMinutes: number): {
+  hours: number;
+  minutes: number;
+} {
+  const hours = Math.floor(totalMinutes / 60);
+  const minutes = Math.round(totalMinutes - hours * 60);
+  return { hours, minutes };
+}
+
+/**
+ * v1.19.1 — average-sleep-per-night headline.
+ *
+ * The third peer of `<SleepDebtCard>` + `<ChronotypeCard>`: identical card
+ * chrome (icon + `text-base` `CardTitle` header, a `space-y-0.5` block with a
+ * bold `text-2xl` primary value and one `text-xs` muted secondary line) so the
+ * three tiles read uniformly in the shared grid row. The figure is the mean of
+ * the canonical per-night asleep totals over the same scorable-night window the
+ * debt + chronotype read — server-authoritative, never recomputed here. Under
+ * the night floor it shows the calm `partial` state and asserts no average.
+ */
+export function AverageSleepCard({ average }: { average: AverageSleepDto }) {
+  const { t } = useTranslations();
+
+  if (average.state === "partial") {
+    return (
+      <Card data-slot="average-sleep-card">
+        <CardHeader className="pb-0">
+          <div className="flex items-center gap-2">
+            <BedDouble className="text-info h-4 w-4" />
+            <CardTitle className="text-base font-semibold">
+              {t("insights.sleep.average.title")}
+            </CardTitle>
+          </div>
+        </CardHeader>
+        <CardContent>
+          <LearningGate
+            message={t("insights.sleep.average.learning", {
+              counted: average.nightsCounted,
+              remaining: average.nightsUntilReady,
+            })}
+          />
+        </CardContent>
+      </Card>
+    );
+  }
+
+  const { hours, minutes } = hoursMinutes(average.averageMinutes);
+
+  return (
+    <Card data-slot="average-sleep-card">
+      <CardHeader className="pb-0">
+        <div className="flex items-center gap-2">
+          <BedDouble className="text-info h-4 w-4" />
+          <CardTitle className="text-base font-semibold">
+            {t("insights.sleep.average.title")}
+          </CardTitle>
+        </div>
+      </CardHeader>
+      <CardContent>
+        <div className="space-y-0.5">
+          <p className="text-2xl font-semibold tabular-nums">
+            {t("insights.sleep.average.value", { hours, minutes })}
+          </p>
+          <p className="text-muted-foreground text-xs">
+            {t("insights.sleep.average.caption", {
+              nights: average.nightsCounted,
+            })}
+          </p>
+        </div>
+      </CardContent>
+    </Card>
+  );
+}

src/components/insights/sleep/average-sleep-section.tsx

@@ -0,0 +1,53 @@
+"use client";
+
+import { useAuth } from "@/hooks/use-auth";
+import { Skeleton } from "@/components/ui/skeleton";
+import { useTranslations } from "@/lib/i18n/context";
+import { useSleepRhythm } from "./use-sleep-rhythm";
+import { AverageSleepCard } from "./average-sleep-card";
+
+/**
+ * v1.19.1 — average-sleep-per-night card on the Sleep view.
+ *
+ * The third peer of `<SleepRhythmSection>` (sleep debt) + `<ChronotypeSection>`
+ * in the shared grid row. Reads the SAME server-authoritative DTO via
+ * `useSleepRhythm`, so it shares the `["sleep-rhythm"]` cache the siblings
+ * already warmed — no extra round-trip. Gated on `enabled` so a source-less
+ * account never fetches.
+ *
+ * States mirror the sibling sections: loading → skeleton, error → quiet inline
+ * notice, settled → the card (which carries its own calm "still learning" copy
+ * for the no-nights-yet case, since the route always returns a full DTO).
+ */
+export function AverageSleepSection({ enabled }: { enabled: boolean }) {
+  const { isAuthenticated } = useAuth();
+  const { t } = useTranslations();
+  const { data, isLoading, isError } = useSleepRhythm(
+    isAuthenticated && enabled,
+  );
+
+  if (!enabled) return null;
+
+  if (isError) {
+    return (
+      <div
+        data-slot="average-sleep-error"
+        role="status"
+        className="bg-card border-border text-muted-foreground rounded-xl border p-4 text-sm"
+      >
+        {t("insights.sleep.rhythm.loadError")}
+      </div>
+    );
+  }
+
+  if (isLoading || !data) {
+    return (
+      <Skeleton
+        data-slot="average-sleep-loading"
+        className="h-28 w-full rounded-xl"
+      />
+    );
+  }
+
+  return <AverageSleepCard average={data.averagePerNight} />;
+}

src/components/insights/sleep/use-sleep-rhythm.ts

@@ -11,10 +11,11 @@ import { apiGet } from "@/lib/api/api-fetch";
 import type {
   SleepDebtDto,
   ChronotypeDto,
+  AverageSleepDto,
   SleepRhythmDto,
 } from "@/lib/insights/derived/sleep-rhythm";
 
-export type { SleepDebtDto, ChronotypeDto, SleepRhythmDto };
+export type { SleepDebtDto, ChronotypeDto, AverageSleepDto, SleepRhythmDto };
 
 /**
  * Read the server-authoritative sleep-rhythm DTO. Gated on `enabled` so a