Prompt for upload re-auth on demand

src/lib/storage/client.ts

@@ -0,0 +1,13 @@
+export async function refreshStorageSession(password: string): Promise<void> {
+    const res = await fetch('/api/storage/session', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ password }),
+    });
+
+    const data = await res.json().catch(() => ({}));
+
+    if (!res.ok) {
+        throw new Error(data.error || 'Failed to confirm password');
+    }
+}