Fix sol muse perf: metadata-only loading instead of full agent composition
Replace get_muse_configs() (which calls get_agent/compose_instructions
and loads facet summaries + entities for every tool-using agent) with
direct _load_prompt_metadata() scanning. Same output, 41s → 0.1s.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>