refactor: Overhaul project structure and role management

This commit implements the first phase of the new architectural vision for the Talia Bot.

Key changes include:
- Renamed the main application directory from `app` to `talia_bot` and updated all associated imports and configurations (`Dockerfile`, tests).
- Replaced the static, `.env`-based permission system with a dynamic, database-driven role management system.
- Introduced a `db.py` module to manage a SQLite database (`users.db`) for user persistence.
- Updated `identity.py` to fetch roles ('admin', 'crew', 'client') from the database.
- Rewrote the `README.md` and `.env.example` to align with the new project specification.
- Refactored the LLM module into the new `modules` structure.

Dockerfile

@@ -2,14 +2,14 @@
 FROM python:3.9-slim
 
 # Set working directory
-WORKDIR /app
+WORKDIR /talia_bot
 
 # Copy and install requirements
 COPY requirements.txt .
 RUN pip install -r requirements.txt
 
 # Copy app code
-COPY app/ .
+COPY talia_bot/ .
 
 # Run the bot
 CMD ["python", "main.py"]