feat: finish all UI/UX improvements from backlog

- nav: aria-label on baby switcher select
- dashboard: active timers show baby name
- growth: PDF export includes percentile band per weight row
- settings: invite link note (permanent, reset if compromised)
- timeline: select mode toggle shows "Annuler" when active
- photos: delete photo from lightbox (PATCHes event metadata)
- notes: invisible date input overlay for date-jump via calendar picker
- IMPROVEMENTS.md: updated checkboxes, 8 remaining → 0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/(app)/growth/page.tsx

@@ -242,6 +242,15 @@ export default function GrowthPage() {
   }
 
   function exportPDF() {
+    function getPercentileBand(ageWeeks: number, weightKg: number): string {
+      const values = PERCENTILE_LABELS.map((_, i) => interpolatePercentile(ageWeeks, i) ?? 0);
+      if (weightKg < values[0]) return "< P3";
+      for (let i = 0; i < values.length - 1; i++) {
+        if (weightKg >= values[i] && weightKg < values[i + 1]) return `${PERCENTILE_LABELS[i]}–${PERCENTILE_LABELS[i + 1]}`;
+      }
+      return "> P97";
+    }
+
     import("jspdf").then(({ default: jsPDF }) => {
       const doc = new jsPDF();
       const pageW = doc.internal.pageSize.getWidth();
@@ -277,7 +286,11 @@ export default function GrowthPage() {
         }
         doc.setTextColor(30, 41, 59);
         doc.text(format(new Date(log.date), "d MMM yyyy", { locale: fr }), COL[0], y);
-        doc.text(log.weight ? (log.weight / 1000).toFixed(3) : "—", COL[1], y);
+        doc.text(log.weight ? (() => {
+          const ageW = getAgeInWeeks(new Date(baby!.birthDate), new Date(log.date));
+          const band = ageW >= 0 && ageW <= 104 ? ` (${getPercentileBand(ageW, log.weight! / 1000)})` : "";
+          return `${(log.weight! / 1000).toFixed(3)}${band}`;
+        })() : "—", COL[1], y);
         doc.text(log.height ? String(log.height) : "—", COL[2], y);
         doc.text(log.headCirc ? String(log.headCirc) : "—", COL[3], y);
         if (log.notes) doc.text(log.notes.slice(0, 30), COL[4], y);