feat: variant + domain bulk ops, enriched INDEX schema
- variants : suffix distribution counts (salva, iran, russian-doctrine, ...)
- enable-variant / disable-variant : bulk by filename suffix
- enable-domain / disable-domain : bulk by frontmatter Domain (live scan)
- INDEX.json now exposes persona, variant, domain
- INDEX.md columns expanded; top-domains and top-variants summaries
- search/disable-search now also match domain & variant
- regex fix: 'c2-hunting' was being parsed as 'c' (digit not allowed)
aaeb31f3ca