feat(chatbot): Implement Kaapi Agentic Flow - #293

Issue

Closes ProjectTech4DevAI/kaapi-backend#1278

Summary

Adds a Chatbot feature to Kaapi Konsole: design a chatbot on a visual canvas, save it, and test it live in a full-page chat.

Chatbot builder (/chatbot)

• New Chatbot tab in the sidebar, shown only to users who have the CHATBOT feature enabled. Opening the URL directly without the feature redirects to home.
• Visual canvas showing the flow Input → Chatbot step → Output.
• The chatbot step is edited directly on the canvas:
  • Name of the chatbot (defaults to "Untitled Chatbot")
  • Configuration + version, picked from the existing saved configs
  • Prompt (goal and the fields to collect), with an expand button for a larger editor
• Save and Discard changes buttons stay disabled until something is edited.
• Save creates a new chatbot session using the current prompt and config.
• After the first save, the chatbot's reference ID is shown on the step.
• On reload, after logging back in, or in a new browser, the last saved chatbot (name, config, prompt) is restored automatically.

Testing the chatbot (/chatbot/chat)

• A Play button icon on the canvas opens the chat in a new tab. It asks you to save first if there are unsaved changes.
• Full-page chat with the sidebar and a breadcrumb: Chatbot › name › session ID.
• Start chat: the bot sends the first message (greeting). Typing is disabled until it does.
• Bot replies arrive live (delivered by webhook), with a typing indicator while the bot is working.
• A status badge shows the session's progress: In progress / Complete / Abandoned / Closed.
• The ↻ Restart button starts a fresh session with the saved flow.
• If a session was replaced by a newer one, typing is disabled and a notice suggests restarting.
• The chat tab follows a new Save made on the canvas tab automatically.
• On logout, all chatbot data (session, saved flow, chat) is cleared so it can't leak to the next user on the same browser.

Checklist

Before submitting a pull request, please ensure that you mark these task.

• Ran npm run dev and npm run build in the repository root and test.
• If you've fixed a bug or added code that is tested