fix: enhance section text update handling and validation

deploy: harden inspector + add RAGAS eval harness

refactor: enhance non-invention guard and tier-aware output handling

feat: implement two-layer hallucination grounding check with 21 new tests

- Added support for RICS survey levels (1, 2, 3) in document uploads and reports, allowing for better tier management and retrieval filtering.

- Replaced timezone.utc with UTC from datetime for consistent datetime handling.

- Updated `.env.example` to include new settings for bulk upload limits and batch processing.

feat: enhance document upload and processing capabilities with new personalisation features

feat: scaffold complete RAG system for RICS-style report generation