POC(nextcloud): add chroot on nextcloud

Bring chroot to nextcloud capability: login on Nextcloud via username="{user}~{folder-uuid}
    Doing a such login will chroot the folder folder-uuid

    If user has several folder as root (parent=None), the login flow will request which
    folder user want to chroot

static/css/views/auth.css

@@ -803,3 +803,50 @@
     font-weight: var(--weight-medium);
     color: var(--color-warning-orange-text);
 }
+
+/* Nextcloud drive picker — radio list of drives the authenticated user
+   can select for this app-password binding. */
+.auth-drive-option {
+    display: flex;
+    align-items: center;
+    gap: 12px;
+    padding: 14px 16px;
+    margin-bottom: 8px;
+    border: 1px solid var(--color-border);
+    border-radius: 12px;
+    cursor: pointer;
+    transition:
+        background 0.2s ease,
+        border-color 0.2s ease;
+}
+
+.auth-drive-option:hover {
+    background: var(--color-bg-hover);
+    border-color: var(--color-accent);
+}
+
+.auth-drive-option input[type="radio"] {
+    margin: 0;
+    accent-color: var(--color-accent);
+}
+
+.auth-drive-option input[type="radio"]:checked ~ .auth-drive-name {
+    font-weight: 600;
+}
+
+.auth-drive-name {
+    flex: 1;
+    color: var(--color-text);
+    font-size: 15px;
+}
+
+.auth-drive-badge {
+    padding: 2px 10px;
+    border-radius: 999px;
+    background: var(--color-accent-gradient);
+    color: var(--color-danger-text);
+    font-size: 11px;
+    font-weight: 700;
+    letter-spacing: 0.5px;
+    text-transform: uppercase;
+}