- Add queries.py: load queries from queries.yaml manifest, execute
  against rdflib graph, return prefixed results
- Add narrative.html.j2: standalone page template for page:true sidecars,
  with full sidebar TOC and SPARQL syntax highlighting
- cli.py: load example TTL files into graph before running queries
- config.py: add sparql_dir option
- manifest.py: include example_queries and standalone_page in manifest
- sidecars.py: add standalone_page and description fields
- renderer.py: render standalone narrative pages; add SPARQL syntax
  highlighting CSS including .sparql-code code padding fix (first-line
  indentation bug caused by inline code padding)
- index.html.j2: TOC links for standalone pages, section cards, queries
  grouped by category, fix IRI regex in SPARQL highlighter (was
  excluding t/g chars, breaking https:// IRIs)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>