feat: contribute opencode-cell-actions to Cell toolbar settings + styles

schema/plugin.json

@@ -1,5 +1,8 @@
 {
   "jupyter.lab.shortcuts": [],
+  "jupyter.lab.toolbars": {
+    "Cell": [{ "name": "opencode-cell-actions", "rank": 100 }]
+  },
   "title": "opencode_bridge",
   "description": "opencode_bridge settings.",
   "type": "object",

style/base.css

@@ -3,3 +3,29 @@
 
     https://jupyterlab.readthedocs.io/en/stable/developer/css.html
 */
+
+/* AI action buttons inside the native Cell toolbar (active cell, top-right). */
+.opencode-cell-actions {
+  display: flex;
+  align-items: center;
+}
+
+.opencode-cell-actions .opencode-btn {
+  border: none;
+  background: transparent;
+  padding: 0 4px;
+  font-size: var(--jp-ui-font-size1);
+  line-height: 20px;
+  cursor: pointer;
+  white-space: nowrap;
+}
+
+.opencode-cell-actions .opencode-btn:disabled {
+  opacity: 0.4;
+  cursor: default;
+}
+
+.opencode-cell-actions .opencode-btn:hover:enabled {
+  background: var(--jp-layout-color2);
+  border-radius: 2px;
+}