Adds yaml / dockerfile / toml / json / xml / groovy / go-mod arms to the
existing 7-arm AST match. parser_version unified to "none-v1" for Tier 2.
synthesize_tier2_document builds a minimal Document (single Block::Code
with raw file text) since Tier 2 has no parse step. allowlist in
ingest_one_asset extended to admit Tier 2 langs.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>