Add Document Type Switcher (Proposal vs. Concept Note)
Created by: Edouard-Legoupil
This change introduces the ability for users to generate either a full project proposal or a shorter concept note directly from the chat interface. It includes a new UI switcher, a corresponding backend template, and logic to ensure the correct template is loaded for each document type.
PR created automatically by Jules for task 4781099085601400977 started by @Edouard-Legoupil