feat(FN-3086): enhance graph navigation with toolbar and keyboard controls

The merge introduces a new Cursor CLI plugin provider with dashboard authentication (FN-3396), enabling Fusion to bundle Cursor's CLI as a native AI model source alongside native shell guide and bridge contract documentation (FN-3577). It also completes the dependency graph plugin's navigation contr

Fusion-Task-Id: FN-3086

plugins/fusion-plugin-dependency-graph/src/GraphToolbar.tsx

@@ -0,0 +1,36 @@
+import { Maximize, RotateCcw, ZoomIn, ZoomOut } from "lucide-react";
+import "./GraphToolbar.css";
+
+export interface GraphToolbarProps {
+  zoom: number;
+  onZoomIn: () => void;
+  onZoomOut: () => void;
+  onFitToGraph: () => void;
+  onResetView: () => void;
+}
+
+export function GraphToolbar({
+  zoom,
+  onZoomIn,
+  onZoomOut,
+  onFitToGraph,
+  onResetView,
+}: GraphToolbarProps) {
+  return (
+    <div className="graph-toolbar" data-testid="graph-toolbar">
+      <button className="btn btn-icon" title="Zoom in (Ctrl+=)" aria-label="Zoom in" onClick={onZoomIn}>
+        <ZoomIn size={16} />
+      </button>
+      <button className="btn btn-icon" title="Zoom out (Ctrl+-)" aria-label="Zoom out" onClick={onZoomOut}>
+        <ZoomOut size={16} />
+      </button>
+      <div className="graph-toolbar__zoom-label" aria-live="polite">{Math.round(zoom * 100)}%</div>
+      <button className="btn btn-icon" title="Fit to graph (Ctrl+Shift+F)" aria-label="Fit to graph" onClick={onFitToGraph}>
+        <Maximize size={16} />
+      </button>
+      <button className="btn btn-icon" title="Reset view (Ctrl+0)" aria-label="Reset view" onClick={onResetView}>
+        <RotateCcw size={16} />
+      </button>
+    </div>
+  );
+}