feat: highlight ProjectKey nodes sharing the same key_name on select

Clicking any ProjectKey node temporarily highlights all other nodes
in the workflow that share the same key_name with an amber color.
Deselecting restores their original colors.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/project_key.js

@@ -201,6 +201,35 @@ app.registerExtension({
             app.graph?.setDirtyCanvas(true, true);
         };
 
+        // --- Highlight all ProjectKey nodes sharing the same key_name on select ---
+        nodeType.prototype.onSelected = function () {
+            const keyWidget = this.widgets?.find(w => w.name === "key_name");
+            const myKey = keyWidget?.value;
+            if (!myKey || !this.graph) return;
+            for (const node of this.graph._nodes) {
+                if (node === this || node.type !== "ProjectKey") continue;
+                const kw = node.widgets?.find(w => w.name === "key_name");
+                if (kw?.value !== myKey) continue;
+                node._savedColor = node.color;
+                node._savedBgColor = node.bgcolor;
+                node.color = "#c8a000";
+                node.bgcolor = "#4a3800";
+            }
+            app.graph?.setDirtyCanvas(true, true);
+        };
+
+        nodeType.prototype.onDeselected = function () {
+            if (!this.graph) return;
+            for (const node of this.graph._nodes) {
+                if (node.type !== "ProjectKey" || !("_savedColor" in node)) continue;
+                node.color = node._savedColor;
+                node.bgcolor = node._savedBgColor;
+                delete node._savedColor;
+                delete node._savedBgColor;
+            }
+            app.graph?.setDirtyCanvas(true, true);
+        };
+
         // --- Sync config on click (lazy, no key refresh to avoid race) ---
         const origOnMouseDown = nodeType.prototype.onMouseDown;
         nodeType.prototype.onMouseDown = function (e, localPos, graphCanvas) {