feat: implémenter système Read It Later natif basé sur tags avec bouton toggle interactif, badge visuel rouge "Read Later", synchronisation bidirectionnelle des tags (readitlater/readlater/toread), intégration dans sidebar et header de navigation, mise à jour automatique des pills de tags, et support complet thème clair/sombre avec états hover et loading

shaarli-pro/css/style.css

@@ -1233,6 +1233,35 @@ input:checked+.theme-slider:before {
     text-decoration: none;
 }
 
+.link-actions .readitlater-toggle-btn {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    width: 36px;
+    height: 36px;
+    background: transparent;
+    border: none;
+    color: var(--text-muted);
+    cursor: pointer;
+    transition: all 0.15s ease;
+    text-decoration: none;
+}
+
+.link-actions .readitlater-toggle-btn i {
+    font-size: 1.15rem;
+    color: inherit;
+}
+
+.link-actions .readitlater-toggle-btn.active {
+    color: #dc2626;
+    background: rgba(220, 38, 38, 0.08);
+}
+
+.link-actions .readitlater-toggle-btn.is-loading {
+    opacity: 0.7;
+    pointer-events: none;
+}
+
 .link-hover-btn:hover {
     background: var(--primary);
     border-color: var(--primary);
@@ -1289,6 +1318,31 @@ input:checked+.theme-slider:before {
     transition: all 0.2s ease;
 }
 
+.link-readlater-badge {
+    position: absolute;
+    top: 0.75rem;
+    right: 3.2rem;
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    height: 32px;
+    padding: 0 0.6rem;
+    border-radius: 0.5rem;
+    background: rgba(239, 68, 68, 0.92);
+    color: #fff;
+    font-size: 0.72rem;
+    font-weight: 700;
+    letter-spacing: 0.02em;
+    text-transform: uppercase;
+    z-index: 10;
+    box-shadow: 0 2px 8px rgba(239, 68, 68, 0.35);
+}
+
+[data-theme="dark"] .link-readlater-badge {
+    background: rgba(248, 113, 113, 0.9);
+    color: #1b0b0b;
+}
+
 .link-visibility-badge i {
     font-size: 1.25rem;
     line-height: 1;
@@ -1487,6 +1541,11 @@ input:checked+.theme-slider:before {
     right: 1.5rem;
 }
 
+.view-list .link-readlater-badge {
+    top: 1.25rem;
+    right: 3.95rem;
+}
+
 /* List view - selection */
 .view-list .link-select-checkbox {
     left: 1rem;