feat(pump): link pump events to milk stock, fix expiry units

- PUMP modal: "Ajouter au stock" toggle with location selector
- Merge option: pick existing today's lot to add volume to (expiry kept)
- On save: POST new MilkStock or PATCH existing volume
- Milk page: expiry input now in hours/days/months per location
- Milk page: "soon" alert threshold scales per location (freezer=7d, fridge=24h, room=2h)

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

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

@@ -37,7 +37,13 @@ function expiryStatus(stock: Stock): "expired" | "soon" | "ok" {
   const now = Date.now();
   const exp = new Date(stock.expiresAt).getTime();
   if (exp <= now) return "expired";
-  if (exp - now < 6 * 60 * 60 * 1000) return "soon"; // < 6h
+  // "soon" threshold scales with location: room <2h, fridge <24h, freezer <7d
+  const remaining = exp - now;
+  const soonMs =
+    stock.location === "freezer" ? 7 * 24 * 3600_000 :
+    stock.location === "fridge"  ? 24 * 3600_000 :
+    2 * 3600_000;
+  if (remaining < soonMs) return "soon";
   return "ok";
 }
 
@@ -51,7 +57,7 @@ export default function MilkPage() {
     volume: "",
     storedAt: localNowString(),
     notes: "",
-    expiryHours: "",
+    expiryCustom: "", // in hours (room), days (fridge), months (freezer)
   });
   const [saving, setSaving] = useState(false);
 
@@ -77,7 +83,13 @@ export default function MilkPage() {
     e.preventDefault();
     if (!selectedBaby) return;
     setSaving(true);
-    const expiryHours = form.expiryHours ? parseFloat(form.expiryHours) : undefined;
+    let expiryCustom: number | undefined;
+    if (form.expiryCustom) {
+      const v = parseFloat(form.expiryCustom);
+      if (location === "fridge") expiryCustom = v * 24;
+      else if (location === "freezer") expiryCustom = v * 24 * 30;
+      else expiryCustom = v;
+    }
     await fetch("/api/milk", {
       method: "POST",
       headers: { "Content-Type": "application/json" },
@@ -87,11 +99,11 @@ export default function MilkPage() {
         storedAt: form.storedAt,
         location,
         notes: form.notes || null,
-        expiryHours,
+        expiryCustom,
       }),
     });
     qc.invalidateQueries({ queryKey: ["milk"] });
-    setForm({ volume: "", storedAt: localNowString(), notes: "", expiryHours: "" });
+    setForm({ volume: "", storedAt: localNowString(), notes: "", expiryCustom: "" });
     setShowForm(false);
     setSaving(false);
   }
@@ -177,7 +189,7 @@ export default function MilkPage() {
                 return (
                   <button key={loc} type="button" onClick={() => {
                     setLocation(loc);
-                    setForm((f) => ({ ...f, expiryHours: "" }));
+                    setForm((f) => ({ ...f, expiryCustom: "" }));
                   }}
                     className={`flex-1 flex flex-col items-center gap-1 py-2 px-1 border rounded-xl text-xs font-medium transition ${
                       location === loc
@@ -191,7 +203,12 @@ export default function MilkPage() {
               })}
             </div>
             <p className="text-[10px] text-slate-400 dark:text-slate-500 mt-1">
-              Durée par défaut : {defaultExpiryHours >= 24 ? `${defaultExpiryHours / 24}j` : `${defaultExpiryHours}h`}
+              Durée par défaut :{" "}
+              {location === "freezer"
+                ? `${defaultExpiryHours / 24 / 30} mois`
+                : location === "fridge"
+                ? `${defaultExpiryHours / 24} jours`
+                : `${defaultExpiryHours}h`}
             </p>
           </div>
 
@@ -202,9 +219,19 @@ export default function MilkPage() {
                 required className={inputCls} placeholder="80" min="1" max="2000" />
             </div>
             <div>
-              <label className="block text-xs font-medium text-slate-600 dark:text-slate-400 mb-1.5">Durée péremption (h)</label>
-              <input type="number" value={form.expiryHours} onChange={(e) => setForm((f) => ({ ...f, expiryHours: e.target.value }))}
-                className={inputCls} placeholder={String(defaultExpiryHours)} min="1" />
+              <label className="block text-xs font-medium text-slate-600 dark:text-slate-400 mb-1.5">
+                Péremption ({location === "freezer" ? "mois" : location === "fridge" ? "jours" : "heures"})
+              </label>
+              <input
+                type="number"
+                value={form.expiryCustom}
+                onChange={(e) => setForm((f) => ({ ...f, expiryCustom: e.target.value }))}
+                className={inputCls}
+                placeholder={
+                  location === "freezer" ? "6" : location === "fridge" ? "4" : "4"
+                }
+                min="1"
+              />
             </div>
           </div>