feat(ui): DatePicker brandé Rubis (remplace input type=date)

Le natif <input type="date"> affiche le calendrier moche du navigateur
(différent par client OS, pas d'alignement palette). On le remplace par
un composant Radix Popover + grille mensuelle Tailwind aux couleurs
Rubis.

Composant : apps/web/src/components/ui/DatePicker.tsx
- Trigger : bouton style Input (border line, focus rubis-glow,
  data-[state=open]:border-rubis pour hint visuel)
- Popover Radix : focus trap, Escape, click outside, animation
- Grille 7×6 (semaine commence lundi, locale FR via date-fns)
- Sélection : bg-rubis text-white + ombre rubis
- Today : ring-inset rubis-glow
- Hover : bg-cream
- Raccourci "Aujourd'hui" en footer

API alignée avec l'usage existant :
- value: string ISO | Date | null
- onChange(date: Date) — l'appelant fait .toISOString() comme avant

Usages migrés :
- ManualInvoiceDialog.tsx : Date d'émission
- factures_.import_.$batchId.tsx : Date d'échéance (avec préservation
  du className aria-invalid pour les low-confidence OCR)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/web/src/components/factures/ManualInvoiceDialog.tsx

@@ -18,6 +18,7 @@ import {
   DialogHeader,
   DialogTitle,
 } from "@/components/ui/Dialog";
+import { DatePicker } from "@/components/ui/DatePicker";
 import { Field } from "@/components/ui/Field";
 import { Input } from "@/components/ui/Input";
 import {
@@ -238,14 +239,10 @@ export function ManualInvoiceDialog({ open, onOpenChange }: ManualInvoiceDialogP
             <form.Field name="issueDate">
               {(field) => (
                 <Field label="Date d'émission" htmlFor={field.name}>
-                  <Input
+                  <DatePicker
                     id={field.name}
-                    type="date"
-                    value={field.state.value.slice(0, 10)}
-                    onChange={(e) => {
-                      const d = new Date(e.target.value);
-                      field.handleChange(d.toISOString());
-                    }}
+                    value={field.state.value}
+                    onChange={(d) => field.handleChange(d.toISOString())}
                   />
                 </Field>
               )}

apps/web/src/components/ui/DatePicker.tsx

@@ -0,0 +1,249 @@
+import * as React from "react";
+import * as Popover from "@radix-ui/react-popover";
+import {
+  Calendar as CalendarIcon,
+  ChevronLeft,
+  ChevronRight,
+} from "lucide-react";
+import {
+  addMonths,
+  eachDayOfInterval,
+  endOfMonth,
+  endOfWeek,
+  format,
+  isSameDay,
+  isSameMonth,
+  isToday,
+  parseISO,
+  startOfMonth,
+  startOfWeek,
+  subMonths,
+} from "date-fns";
+import { fr } from "date-fns/locale";
+
+import { cn } from "@/lib/utils";
+
+/**
+ * DatePicker brandé Rubis — alternative au natif `<input type="date">` qui
+ * affiche le calendrier moche du navigateur. Utilise Radix Popover pour le
+ * positionnement et l'accessibilité (focus trap, Escape, click outside).
+ *
+ * Palette : trigger en `Input`-style (border line, focus rubis), grille avec
+ * jour sélectionné `bg-rubis text-white` + ombre rubis, today `ring-rubis-glow`.
+ *
+ * I/O :
+ *  - `value` accepte string ISO (cf. usage existant Tanstack Form) ou `Date`.
+ *  - `onChange(date: Date)` rend toujours un Date que l'appelant convertit
+ *    via `.toISOString()` ou autre format selon son champ.
+ */
+export type DatePickerProps = {
+  value?: string | Date | null;
+  onChange: (date: Date) => void;
+  placeholder?: string;
+  id?: string;
+  className?: string;
+  disabled?: boolean;
+  "aria-invalid"?: boolean;
+};
+
+function toDate(value: DatePickerProps["value"]): Date | null {
+  if (!value) return null;
+  if (value instanceof Date) return value;
+  try {
+    const d = parseISO(value);
+    return Number.isNaN(d.getTime()) ? null : d;
+  } catch {
+    return null;
+  }
+}
+
+export function DatePicker({
+  value,
+  onChange,
+  placeholder = "Choisir une date",
+  id,
+  className,
+  disabled,
+  "aria-invalid": ariaInvalid,
+}: DatePickerProps) {
+  const date = toDate(value);
+  const [open, setOpen] = React.useState(false);
+  const [viewMonth, setViewMonth] = React.useState<Date>(date ?? new Date());
+
+  // Re-sync viewMonth quand la valeur externe change (reset de form, etc.)
+  React.useEffect(() => {
+    if (date) setViewMonth(date);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [date?.getTime()]);
+
+  const handleSelect = (d: Date) => {
+    onChange(d);
+    setOpen(false);
+  };
+
+  return (
+    <Popover.Root open={open} onOpenChange={setOpen}>
+      <Popover.Trigger asChild>
+        <button
+          id={id}
+          type="button"
+          disabled={disabled}
+          aria-invalid={ariaInvalid}
+          className={cn(
+            // Base — alignée avec Input.tsx pour cohérence visuelle
+            "flex w-full items-center justify-between gap-2 rounded-default border border-line bg-white px-3.5 py-3 text-left",
+            "font-sans text-base lg:text-[15px]",
+            // Transitions
+            "transition-[border-color,box-shadow] duration-150",
+            // Focus
+            "focus:outline-none focus:border-rubis focus:ring-4 focus:ring-rubis-glow",
+            // Open state — petit hint visuel
+            "data-[state=open]:border-rubis data-[state=open]:ring-4 data-[state=open]:ring-rubis-glow",
+            // États
+            "disabled:cursor-not-allowed disabled:bg-cream-2 disabled:text-ink-3",
+            "aria-[invalid=true]:border-rubis-deep aria-[invalid=true]:bg-rubis-glow/30",
+            className,
+          )}
+        >
+          <span className={cn(date ? "text-ink" : "text-ink-3")}>
+            {date
+              ? format(date, "d MMMM yyyy", { locale: fr })
+              : placeholder}
+          </span>
+          <CalendarIcon className="h-4 w-4 shrink-0 text-ink-3" aria-hidden />
+        </button>
+      </Popover.Trigger>
+      <Popover.Portal>
+        <Popover.Content
+          align="start"
+          sideOffset={6}
+          className={cn(
+            "z-50 w-[20rem] rounded-default border border-line bg-white p-3",
+            "shadow-[0_8px_24px_rgba(26,20,16,0.10)]",
+            // Animation discrète
+            "data-[state=open]:animate-in data-[state=open]:fade-in-0 data-[state=open]:zoom-in-95",
+            "data-[state=closed]:animate-out data-[state=closed]:fade-out-0",
+          )}
+        >
+          <CalendarGrid
+            viewMonth={viewMonth}
+            selectedDate={date}
+            onSelect={handleSelect}
+            onMonthChange={setViewMonth}
+          />
+        </Popover.Content>
+      </Popover.Portal>
+    </Popover.Root>
+  );
+}
+
+// ---------------------------------------------------------------------------
+// Grille interne — header (chevrons + mois courant) + 7×6 jours + raccourci
+// "Aujourd'hui". Semaine commence lundi (FR).
+// ---------------------------------------------------------------------------
+
+type CalendarGridProps = {
+  viewMonth: Date;
+  selectedDate: Date | null;
+  onSelect: (date: Date) => void;
+  onMonthChange: (date: Date) => void;
+};
+
+function CalendarGrid({
+  viewMonth,
+  selectedDate,
+  onSelect,
+  onMonthChange,
+}: CalendarGridProps) {
+  const monthStart = startOfMonth(viewMonth);
+  const monthEnd = endOfMonth(viewMonth);
+  const gridStart = startOfWeek(monthStart, { weekStartsOn: 1 }); // Lundi
+  const gridEnd = endOfWeek(monthEnd, { weekStartsOn: 1 });
+
+  const days = eachDayOfInterval({ start: gridStart, end: gridEnd });
+  const weekDays = ["L", "M", "M", "J", "V", "S", "D"];
+
+  return (
+    <div>
+      {/* Header mois — chevrons + label */}
+      <div className="mb-3 flex items-center justify-between">
+        <button
+          type="button"
+          onClick={() => onMonthChange(subMonths(viewMonth, 1))}
+          className="rounded-default p-1.5 text-ink-2 transition-colors hover:bg-cream hover:text-rubis focus:outline-none focus:ring-2 focus:ring-rubis-glow"
+          aria-label="Mois précédent"
+        >
+          <ChevronLeft className="h-4 w-4" />
+        </button>
+        <div className="text-sm font-semibold capitalize text-ink">
+          {format(viewMonth, "MMMM yyyy", { locale: fr })}
+        </div>
+        <button
+          type="button"
+          onClick={() => onMonthChange(addMonths(viewMonth, 1))}
+          className="rounded-default p-1.5 text-ink-2 transition-colors hover:bg-cream hover:text-rubis focus:outline-none focus:ring-2 focus:ring-rubis-glow"
+          aria-label="Mois suivant"
+        >
+          <ChevronRight className="h-4 w-4" />
+        </button>
+      </div>
+
+      {/* Labels jours (L M M J V S D) */}
+      <div className="mb-2 grid grid-cols-7">
+        {weekDays.map((d, i) => (
+          <div
+            key={i}
+            className="text-center text-[11px] font-semibold uppercase tracking-wider text-ink-3"
+          >
+            {d}
+          </div>
+        ))}
+      </div>
+
+      {/* Grille 7×6 jours */}
+      <div className="grid grid-cols-7 gap-1">
+        {days.map((day) => {
+          const isOutside = !isSameMonth(day, viewMonth);
+          const isSelected = selectedDate ? isSameDay(day, selectedDate) : false;
+          const isCurrent = isToday(day);
+          return (
+            <button
+              key={day.toISOString()}
+              type="button"
+              onClick={() => onSelect(day)}
+              className={cn(
+                "aspect-square w-full rounded-default text-sm font-medium tabular-nums",
+                "transition-colors duration-100",
+                "focus:outline-none focus:ring-2 focus:ring-rubis-glow",
+                // Jour hors mois courant — discret
+                isOutside && !isSelected && "text-ink-3/50",
+                // Jour normal du mois — hover crème
+                !isOutside && !isSelected && "text-ink hover:bg-cream",
+                // Today (non sélectionné) — petit ring rubis-glow pour repère
+                isCurrent && !isSelected && "ring-1 ring-inset ring-rubis-glow",
+                // Sélectionné — bg rubis + glow
+                isSelected &&
+                  "bg-rubis text-white shadow-[0_2px_8px_rgba(159,18,57,0.30)]",
+              )}
+              aria-pressed={isSelected || undefined}
+              aria-current={isCurrent ? "date" : undefined}
+            >
+              {format(day, "d")}
+            </button>
+          );
+        })}
+      </div>
+
+      {/* Raccourci "Aujourd'hui" */}
+      <div className="mt-3 border-t border-line pt-3">
+        <button
+          type="button"
+          onClick={() => onSelect(new Date())}
+          className="w-full rounded-default py-1.5 text-sm font-semibold text-rubis transition-colors hover:bg-rubis-glow/40 hover:text-rubis-deep focus:outline-none focus:ring-2 focus:ring-rubis-glow"
+        >
+          Aujourd&apos;hui
+        </button>
+      </div>
+    </div>
+  );
+}

apps/web/src/routes/_app/factures_.import_.$batchId.tsx

@@ -26,6 +26,7 @@ import { formatEuros } from "@/lib/format";
 
 import { Button } from "@/components/ui/Button";
 import { Card } from "@/components/ui/Card";
+import { DatePicker } from "@/components/ui/DatePicker";
 import { Eyebrow } from "@/components/ui/Eyebrow";
 import { Field } from "@/components/ui/Field";
 import { Input } from "@/components/ui/Input";
@@ -358,13 +359,12 @@ function ImportReviewPage() {
             </Field>
 
             <Field label="Date d'échéance" htmlFor="dueDate">
-              <Input
+              <DatePicker
                 id="dueDate"
-                type="date"
-                value={draft.dueDate.slice(0, 10)}
-                onChange={(e) =>
+                value={draft.dueDate}
+                onChange={(d) =>
                   update({
-                    dueDate: new Date(e.target.value).toISOString(),
+                    dueDate: d.toISOString(),
                   })
                 }
                 className={cn(isLowConfidence("dueDate") && "border-rubis")}