Default LLM to Hugging Face on Spaces; fix HF_TOKEN settings merge

Enhance Docker configuration and Hugging Face integration

Enhance environment configuration and API documentation for Milestone 11

Enhance API and Streamlit UI with new timeout handling and telemetry adjustments

Implement Milestone 8 by adding new endpoints for URL ingestion and collection management. Introduce `httpx` as a dependency for handling URL downloads, and enhance the API with endpoints for listing and deleting collections. Update request and response models to support new functionalities, and refactor existing routes for improved clarity and organization.

Implement Milestone 7 by introducing background ingestion jobs. Update environment configuration to include job database path, enhance job tracking with new endpoints, and refactor ingestion logic to support asynchronous processing. Modify response models to include job details and ensure proper initialization of the jobs database on startup.

Implement Milestone 6 by adding audit persistence functionality. Introduce `aiosqlite` as a dependency, update the audit routes to support event logging and retrieval, and enhance the query endpoint to persist audit records. Modify response models to include audit details and ensure proper initialization of the audit database on startup.

Implement Milestone 5 by adding retrieval and grounded LLM answer functionality. Update query endpoint to return grounded answers with source citations, enhance response models to include answer and sources, and refactor retriever logic to support new chunk structure and grounding mechanism. Update milestones documentation to reflect new dependencies and expected outputs.

Refactor embedding function creation and document loading. Update ingest and query routes to remove unnecessary settings parameters, streamline chunking logic, and enhance load_documents function to handle both string and list inputs. Adjust model name in embedder for consistency with OpenAI API.

Enhance configuration and ingestion functionality for Milestone 4. Update .env.example with new environment variables, expand milestones documentation with integration details, and add necessary dependencies to pyproject.toml and requirements.txt. Refactor ingest and query routes to support file uploads and retrieval, implementing validation and error handling. Update settings to include new model configurations and parameters for chunking and embedding.

Implement Milestone 3 by adding configuration and request/response contracts. Introduce new models for requests and responses, enhance route handlers with schema validation, and update dependencies to include pydantic-settings. Update audit, ingest, jobs, and query routes to utilize new models and improve response structures.

Add Milestone 2 with route skeletons and update main.py to include new routes. Enhance health check response with app details.

Update README.md to include environment setup instructions and add requirements.txt and .env files