LCFS - AI chatbot feature flag

**Describe the task**
Create a proper feature flag for the AI chatbot that allows it to be enabled or disabled based on the environment.

**Purpose**
This ensures the AI chatbot can be safely tested in development without being available in test or production environments, enabling controlled rollout.

**Acceptance Criteria**
- [ ] Feature flag exists specifically for the AI chatbot.
- [ ] Feature flag can be configured separately for dev, test, and prod environments.
- [ ] Chatbot is enabled in development environment by default.
- [ ] Chatbot is disabled in test and production environments by default.
- [ ] Chatbot UI and backend logic respect the state of the feature flag.
- [ ] Documentation is created for how to enable/disable the feature flag.

**Additional context**
- Use environment variables or the existing feature flag framework in the project.
- Ensure no chatbot scripts or services load when disabled.