Summary

• add a connector-neutral search_documents_fts index over entity metadata, observations, connector search metadata, and hydrated shadows
• emit loc_search metadata from first-party connectors for aliases, source URLs, and provider-specific searchable text
• rank loc search results by matched field and expose optional match_context snippets in human and JSON output

Verification

• cargo test --workspace
• isolated target/debug/loc search smoke test for title, alias, source URL, body, JSON match_context, and human match: output
• git diff --check HEAD~3..HEAD