feat(canvas): set default tool to Move and refine canvas navigation interactions

web/src/components/canvas/infinite-canvas.tsx

@@ -113,7 +113,7 @@ export function InfiniteCanvas({ containerRef, viewport, tool, backgroundMode =
         const isBackgroundClick = !target?.closest("[data-node-id],[data-connection-id]");
         const temporaryTool = event.ctrlKey || isSpacePressed;
         const activeTool = temporaryTool ? (tool === "select" ? "pan" : "select") : tool;
-        const shouldPan = event.button === 1 || (event.button === 0 && activeTool === "pan");
+        const shouldPan = event.button === 1 || (event.button === 0 && activeTool === "pan" && isBackgroundClick);
 
         if (shouldPan) {
             event.preventDefault();

web/src/pages/canvas/project.tsx

@@ -199,7 +199,7 @@ function InfiniteCanvasPage() {
     const [chatSessions, setChatSessions] = useState<CanvasAssistantSession[]>([]);
     const [activeChatId, setActiveChatId] = useState<string | null>(null);
     const [viewport, setViewport] = useState<ViewportTransform>({ x: 0, y: 0, k: 1 });
-    const [canvasTool, setCanvasTool] = useState<"select" | "pan">("select");
+    const [canvasTool, setCanvasTool] = useState<"select" | "pan">("pan");
     const [size, setSize] = useState({ width: 1200, height: 720 });
     const [selectedNodeIds, setSelectedNodeIds] = useState<Set<string>>(new Set());
     const [selectedConnectionId, setSelectedConnectionId] = useState<string | null>(null);