feat(canvas): enhance edge insertion and local node data handling

- Added support for new edge insertion features, including default edge types and improved layout calculations.
- Introduced local node data persistence during flow reconciliation to ensure data integrity.
- Updated connection drop menu to handle edge insertions and node interactions more effectively.
- Enhanced testing for edge insert layout and local node data management.

components/canvas/__tests__/canvas-connection-drop-menu.test.tsx

@@ -0,0 +1,85 @@
+// @vitest-environment jsdom
+
+import React from "react";
+import { act } from "react";
+import { createRoot, type Root } from "react-dom/client";
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+import { CanvasConnectionDropMenu } from "@/components/canvas/canvas-connection-drop-menu";
+import type { CanvasNodeTemplate } from "@/lib/canvas-node-templates";
+
+vi.mock("@/components/ui/command", () => ({
+  Command: ({ children }: { children: React.ReactNode }) => <div>{children}</div>,
+  CommandEmpty: ({ children }: { children: React.ReactNode }) => <div>{children}</div>,
+  CommandInput: () => <input aria-label="command-input" />,
+  CommandList: ({ children }: { children: React.ReactNode }) => <div>{children}</div>,
+}));
+
+vi.mock("@/components/canvas/canvas-node-template-picker", () => ({
+  CanvasNodeTemplatePicker: ({
+    onPick,
+  }: {
+    onPick: (template: CanvasNodeTemplate) => void;
+  }) => (
+    <button
+      type="button"
+      data-testid="pick-template"
+      onClick={() => onPick({ type: "note", label: "Notiz" } as CanvasNodeTemplate)}
+    >
+      pick
+    </button>
+  ),
+}));
+
+(globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+
+describe("CanvasConnectionDropMenu", () => {
+  let root: Root | null = null;
+  let container: HTMLDivElement | null = null;
+
+  afterEach(() => {
+    if (root) {
+      act(() => {
+        root?.unmount();
+      });
+    }
+    container?.remove();
+    root = null;
+    container = null;
+    vi.restoreAllMocks();
+  });
+
+  it("renders using a generic anchor and forwards template picks", () => {
+    const onPick = vi.fn<(template: CanvasNodeTemplate) => void>();
+    const onClose = vi.fn();
+
+    container = document.createElement("div");
+    document.body.appendChild(container);
+    root = createRoot(container);
+
+    act(() => {
+      root?.render(
+        <CanvasConnectionDropMenu
+          anchor={{ screenX: 140, screenY: 200 }}
+          onClose={onClose}
+          onPick={onPick}
+        />,
+      );
+    });
+
+    const dialog = document.querySelector('[role="dialog"]');
+    expect(dialog).not.toBeNull();
+
+    const pickButton = document.querySelector('[data-testid="pick-template"]');
+    if (!(pickButton instanceof HTMLButtonElement)) {
+      throw new Error("Template pick button was not rendered");
+    }
+
+    act(() => {
+      pickButton.click();
+    });
+
+    expect(onPick).toHaveBeenCalledTimes(1);
+    expect(onClose).toHaveBeenCalledTimes(1);
+  });
+});