feat(rag): docs ingestion + UI/bus enhancements (P3 continuation)

fix: llm.chat IndexError (lazy Ollama warm + safe _resolve_backend fallback) + chat self-send returns direct

fix: Python 3.10 compat — replace datetime.UTC with timezone.utc shim

Quality improvements: Unicode chars, Token class, imports, type hints, formatting

fix: complete easter egg rewrite using Gradio 6 js= API

Fix: Additional ruff auto-fixes (30 issues fixed)

fix: re-apply Python 3.10 UTC fixes across all 10 files

Fix: Ruff linting issues - SIM/E402/F401 violations

fix: re-apply Python 3.10 UTC compatibility (was reverted by formatter)

fix: easter-egg ticker now properly works in Gradio app

fix: Python 3.10 compatibility - replace UTC import with timezone.utc

feat: WebLLM browser agent with PeerJS mesh, HybridRAG, news signals, and easter-egg ticker

fix: Python 3.10 compatibility for HF Space (Python 3.10 env)

fix: 0 test failures; FileService; real RagService; emergency probe; chat return

feat: Phase 2 (M14-M25, X05-X07) + Phase 3 experimental (M26-M31) + E2E tests + docs

feat: implement all M01-M13, X01-X04 modules + quality gate fixes