Implement a node duplication feature

[shige]

Task description

Implement a node duplication feature within an Agent.

Background

Currently, there is no way to easily duplicate nodes (such as Text-Gen) within an Agent. This requires users to manually recreate and reconfigure nodes from scratch when they want to experiment with variations of existing nodes, such as modifying prompts for comparison. This process is time-consuming and inefficient, especially when multiple similar nodes are needed. Users have to resort to temporary workarounds like saving prompt text in external editors.

Agent duplication functionality is being handled separately in issue #303.

TODO (Optional)

• Implement a feature to duplicate a selected node within the current Agent.
• Verify that duplicated nodes function correctly.
• Ensure that node duplication is limited to within the current Agent, and does not allow duplication from another Agent.

Additional notes (Optional)

This feature will not include the ability to copy nodes between different Agents.

[shige]

FYI:

Since there are already features available for developers, it might be a good idea to implement them based on the following URL for reference.

📁 app/dev/copy-agent