Step 6 (first slice). Now that `vdb` installs onto PATH, repoint the top-level
docs at it while keeping the standalone engines documented (deployed-copy +
systemd still supported):

- README quickstart drives `vdb context add` → `vdb index` → `vdb serve`, with a
  "no install?" note for the standalone `python3 vault-indexer.py/--vault-root`
  path; MCP registration (Claude Code, OpenCode) uses `vdb serve --vault …`;
  models/agents/fixtures snippets use `vdb models/agents/fixtures`; Files table
  gains the `vdb/` package rows and drops the stale "vdb-menu = scaffold" line.
- CLAUDE.md commands block becomes `vdb …` with standalone equivalents inline; a
  new "Two ways to point the engines at a vault" section explains runtime
  resolution vs. the hardcoded-constant deployed-copy path; apply_config note
  points at vdb/vdb_config.py.

Docs-only; tool count (28) unchanged. Remaining ref sweep (harness docs, skill
SKILL.md files, docs/setup-guide.md, AGENTS.md, tests/tui/README) is a follow-up.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>