Monoagent streaming

[jmsevin]

This pull request introduces significant improvements to the chat experience, focusing on real-time streaming of agent answers, enhanced user feedback during processing, and better API environment handling. The main changes include switching the chat agent's answer retrieval to a streaming approach, providing dynamic status updates to the user during answer formulation, and refactoring API utility functions for improved local development support.

Chat streaming and user feedback improvements:

• Replaces the previous synchronous agent answer fetching with a streaming implementation in useChatStore, allowing incremental updates to the assistant's message and dynamic handling of processing steps and metadata. This results in a smoother and more informative chat experience for users.
• Introduces ChatProcessingMetadata and related logic in the store to extract, normalize, and display processing steps (e.g., "fetching resources", "analyzing resources", "generating answer") received from the backend, with support for custom labels. [1] [2] [3]
• Updates the UI to display the current processing step label in the loading component, and ensures the chat area scrolls to the bottom on updates for better usability. [1] [2] [3]

Internationalization:

• Adds English and French translations for the new chat processing steps, ensuring clear and localized user feedback during different stages of answer formulation. [1] [2]

API utility refactoring:

• Refactors API utility functions to support a local development proxy (/__welearn_api_proxy__) when running against a localhost API, centralizing API root logic and simplifying endpoint construction. This change affects all API calls, including GET, POST, DELETE, streaming, and bookmark operations. [1] [2] [3] [4] [5] [6] [7] [8]

Additional UI improvements:

• Updates the chat bubble key in the message list to prevent rendering issues and improve reactivity.
• Refines the loading component to accept and display a label, improving clarity during processing.