v0.8.5 fix pinning

frontend/src/components/Sidebar.css

@@ -154,6 +154,55 @@
   flex-shrink: 0;
 }
 
+/* Conversation pin button — visible on hover (desktop) or always when pinned */
+.group-item-actions {
+  display: flex;
+  align-items: center;
+  gap: 4px;
+  flex-shrink: 0;
+}
+
+.conv-pin-btn {
+  display: none;
+  align-items: center;
+  justify-content: center;
+  width: 22px;
+  height: 22px;
+  border-radius: 4px;
+  color: var(--text-tertiary);
+  opacity: 0;
+  transition: opacity var(--transition), color var(--transition), background var(--transition);
+  flex-shrink: 0;
+}
+.conv-pin-btn:hover { background: var(--border); color: var(--primary); }
+.conv-pin-btn.pinned {
+  display: flex;
+  opacity: 1;
+  color: var(--primary);
+}
+.group-item:hover .conv-pin-btn {
+  display: flex;
+  opacity: 0.7;
+}
+.group-item:hover .conv-pin-btn:hover { opacity: 1; }
+
+/* Small pin icon inline before the name when conversation is pinned */
+.conv-pin-indicator {
+  display: inline;
+  vertical-align: middle;
+  margin-right: 3px;
+  color: var(--primary);
+  opacity: 0.7;
+  position: relative;
+  top: -1px;
+}
+
+/* Pinned conversations get a subtle left accent */
+.group-item.is-pinned {
+  border-left: 2px solid var(--primary);
+  padding-left: 14px;
+}
+
 .group-last-msg {
   font-size: 13px;
   color: var(--text-secondary);