Disable LLM RAG sanitisation by default on HF Spaces to fix slow ingestion.

Speed up generation and ingestion; add live report progress on /status.

Default report generation to standard RAG/LLM on e561e67 baseline with /health verification.

feat: RAG upload sanitisation layer before vector indexing

feat: async pipeline, job queue, generation hardening, and docs

feat: AI interference levels (minimum|medium|maximum) UI, API, prompts, generation

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

feat: FAISS-only vector store (remove Chroma)

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

fix: comprehensive codebase review fixes (critical + major + minor issues)

fix: apply all bug fixes and improvements (embeddings, cache, postprocess, frontend, tests)

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