Wrap llm.generate() in compile_concept with a broad try/except; log a warning and return an empty ConceptPage (no crash) when the LLM endpoint is unreachable. Add logging module import. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Adds wiki/concepts.yaml (5 curated seeds: discrete-conformal-map, circle-packing, lobachevsky-function, discrete-yamabe-flow, hyperideal-tetrahedron) and codex/wiki.py with full load_concepts() implementation (Concept dataclass, YAML parser, graceful empty list). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>