fix(charts): "7-Tage-Trend" label + numeric trend indicator on every chart incl. mood

Marc reported v1.4.15 A4 didn't fully land:
- DE label still read "7-Tage-Schnitt" / "7T-Schnitt" in places
- mood tile showed no numeric trend delta even though other tiles did

i18n rename:
- de.json + en.json: trend7dShort, movingAverage7d, moodMA all read
  "7-Tage-Trend" / "7-day trend". The legacy "7T:" / "7d:" header on
  the avg7 line is preserved for tiles that haven't been migrated to
  the trend7Delta API.

trend-delta fallback:
- summaryToTrend7Delta() now falls back to slope30 (projected onto
  7 days) when slope7 is null. Mood entries are typically logged
  less than daily, so slope7 needs ≥ 2 points within the trailing
  7-day window — for sparser users that came back null and the tile
  silently dropped the delta indicator. slope30 still answers "is
  this metric drifting?" so we project that onto the 7-day window
  for label parity.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

messages/de.json

@@ -587,13 +587,14 @@
     "bodyWater": "Körperwasser",
     "boneMass": "Knochenmasse",
     "spo2": "SpO₂",
-    "movingAverage7d": "7T-Schnitt",
+    "movingAverage7d": "7-Tage-Trend",
     "avg7dShort": "7T",
     "avg30dShort": "30T",
-    "trend7dShort": "7T-Trend",
+    "trend7dShort": "7-Tage-Trend",
     "trend": "Trend",
     "targetRanges": "Zielbereiche",
     "perWeek": "/Woche",
+    "totalDelta": "Gesamt",
     "selectMedication": "Medikament wählen",
     "noComplianceData": "Keine Compliance-Daten verfügbar",
     "history": "Verlauf",
@@ -603,7 +604,7 @@
     "colorRed": "Rot:",
     "mood": "Stimmung",
     "moodScore": "Stimmungswert",
-    "moodMA": "7-Tage-Schnitt",
+    "moodMA": "7-Tage-Trend",
     "moodLabel1": "Lausig",
     "moodLabel2": "Schlecht",
     "moodLabel3": "Okay",
@@ -1102,7 +1103,7 @@
     "rawDataWarning": "Rohdaten aktiv: Die KI erhält zusätzlich anonymisierte Messpunkte der letzten 30 Tage für eine präzisere Auswertung.",
     "regenerateInsights": "Reports neu generieren",
     "regenerateSuccess": "Reports wurden neu generiert",
-    "regenerateRateLimit": "Bitte warte — maximal 2 Analysen pro Stunde.",
+    "regenerateRateLimit": "Bitte warte — du hast das stündliche Limit für Analysen erreicht.",
     "lastGeneratedAt": "Zuletzt generiert",
     "ai": {
       "title": "KI-Insights",

messages/en.json

@@ -587,13 +587,14 @@
     "bodyWater": "Body water",
     "boneMass": "Bone mass",
     "spo2": "SpO₂",
-    "movingAverage7d": "7d avg",
+    "movingAverage7d": "7-day trend",
     "avg7dShort": "7d",
     "avg30dShort": "30d",
-    "trend7dShort": "7d trend",
+    "trend7dShort": "7-day trend",
     "trend": "Trend",
     "targetRanges": "Target ranges",
     "perWeek": "/week",
+    "totalDelta": "Total",
     "selectMedication": "Select medication",
     "noComplianceData": "No compliance data available",
     "history": "History",
@@ -603,7 +604,7 @@
     "colorRed": "Red:",
     "mood": "Mood",
     "moodScore": "Mood Score",
-    "moodMA": "7-Day Average",
+    "moodMA": "7-day trend",
     "moodLabel1": "Awful",
     "moodLabel2": "Bad",
     "moodLabel3": "Okay",
@@ -1102,7 +1103,7 @@
     "rawDataWarning": "Raw mode enabled: AI receives additional anonymized points from the last 30 days for higher analysis accuracy.",
     "regenerateInsights": "Regenerate reports",
     "regenerateSuccess": "Reports regenerated successfully",
-    "regenerateRateLimit": "Please wait — max 2 analyses per hour.",
+    "regenerateRateLimit": "Please wait — you've hit the hourly limit for analyses.",
     "lastGeneratedAt": "Last generated",
     "ai": {
       "title": "AI Insights",

src/components/charts/__tests__/trend-card-7d-trend.test.tsx

@@ -50,7 +50,7 @@ describe("<TrendCard> 7-day trend label", () => {
       />,
     );
     // New label flips on for the trend variant.
-    expect(html).toContain("7d trend");
+    expect(html).toContain("7-day trend");
     // Legacy avg7 short label must NOT appear in the trend variant —
     // this is the whole point of the rename.
     expect(html).not.toContain(">7d:<");
@@ -65,13 +65,13 @@ describe("<TrendCard> 7-day trend label", () => {
       />,
       "de",
     );
-    expect(html).toContain("7T-Trend");
+    expect(html).toContain("7-Tage-Trend");
   });
 
   it("keeps the legacy avg7 label when no delta is supplied (back-compat)", () => {
     const html = render(<TrendCard {...baseProps} />);
     expect(html).toContain("7d");
-    expect(html).not.toContain("7d trend");
+    expect(html).not.toContain("7-day trend");
   });
 
   it("renders a positive delta with `+` sign and one decimal", () => {

src/lib/analytics/__tests__/trend-delta.test.ts

@@ -19,8 +19,9 @@ describe("summaryToTrend7Delta()", () => {
     expect(summaryToTrend7Delta(undefined)).toBeNull();
   });
 
-  it("returns null when slope7 is not computable (insufficient data)", () => {
+  it("returns null when neither slope7 nor slope30 is computable", () => {
     expect(summaryToTrend7Delta({ slope7: null })).toBeNull();
+    expect(summaryToTrend7Delta({ slope7: null, slope30: null })).toBeNull();
   });
 
   it("projects slope (units per day) over a 7-day window", () => {
@@ -36,4 +37,29 @@ describe("summaryToTrend7Delta()", () => {
   it("returns 0 for a stable slope (the tile then paints ±0)", () => {
     expect(summaryToTrend7Delta({ slope7: STABLE })).toBe(0);
   });
+
+  it("falls back to slope30 when slope7 is null (sparse metrics like mood)", () => {
+    // v1.4.16 fix A4: mood-tile showed no trend number for users who
+    // log mood < daily because slope7 needs ≥2 points within the
+    // trailing 7-day window. slope30 still answers "is this metric
+    // drifting?" so we project that onto 7 days for label parity.
+    expect(
+      summaryToTrend7Delta({ slope7: null, slope30: RISING_HALF_PER_DAY }),
+    ).toBe(3.5);
+    expect(
+      summaryToTrend7Delta({
+        slope7: null,
+        slope30: FALLING_TENTH_PER_DAY,
+      }),
+    ).toBeCloseTo(-0.7, 3);
+  });
+
+  it("prefers slope7 over slope30 when both are present", () => {
+    expect(
+      summaryToTrend7Delta({
+        slope7: RISING_HALF_PER_DAY,
+        slope30: FALLING_TENTH_PER_DAY,
+      }),
+    ).toBe(3.5);
+  });
 });

src/lib/analytics/trend-delta.ts

@@ -12,9 +12,17 @@
  *   delta = slope.slope * 7  // units per day → unit delta over 7d
  *
  * The trend-card then paints the delta with metric-aware sentiment
- * colour (up-good vs up-bad).  Returning `null` when slope7 is not
- * available keeps the tile rendering the legacy avg label for back-
- * compat with call sites that haven't been migrated.
+ * colour (up-good vs up-bad).
+ *
+ * v1.4.16 Fix A4: fall back to slope30 (projected onto 7 days) when
+ * slope7 is unavailable. Some metrics (mood, sleep) have <2 entries
+ * within the trailing 7-day window for users who don't log daily,
+ * which used to surface as a missing delta on the dashboard tile —
+ * Marc's complaint: "Bei Stimmung wird zum Beispiel kein Trend in
+ * Zahlen dargestellt." A 30-day slope still answers the question
+ * "is this metric drifting up or down?" — we just project it onto
+ * a 7-day window for label consistency. Returning `null` is reserved
+ * for the truly insufficient case where neither slope is available.
  *
  * Pure & deterministic — pinned by unit test.
  */
@@ -22,14 +30,26 @@ import type { TrendSlope } from "@/lib/analytics/trends";
 
 export interface TrendCapableSummary {
   slope7: TrendSlope | null;
+  slope30?: TrendSlope | null;
 }
 
 export function summaryToTrend7Delta(
   summary: TrendCapableSummary | undefined | null,
 ): number | null {
-  const slope7 = summary?.slope7;
-  if (!slope7) return null;
-  // slope.slope is units per day (see lib/analytics/trends.ts) → 7 days
-  // is the projected end-to-end delta of the regression line.
-  return slope7.slope * 7;
+  if (!summary) return null;
+  // Primary: trailing-7-day linear-regression slope projected to a
+  // 7-day window. slope.slope is units per day (see
+  // lib/analytics/trends.ts).
+  if (summary.slope7) {
+    return summary.slope7.slope * 7;
+  }
+  // Fallback: slope30 projected onto 7 days. Same units (per day) so
+  // we still multiply by 7. This keeps the delta visible for sparser
+  // metrics (mood, sleep) that don't accumulate enough points in
+  // every trailing 7-day window. The arrow + colour interpretation
+  // stays correct because slope30 is computed the same way.
+  if (summary.slope30) {
+    return summary.slope30.slope * 7;
+  }
+  return null;
 }