v0.17.0 — scripts check + serve + fleet dashboard

• scripts check (required): shell scripts live under scripts/, a
  scripts/dev.sh stands up the basic dev environment, and the README points at
  it. Hidden and vendored trees (.githooks/, node_modules/, …) are never
  scanned — git hooks belong in .githooks/. Configurable via [scripts]
  (dir, dev, allow). Housekeeping now ships its own scripts/dev.sh.
• Fleet dashboard now carries a second table: every open PR and issue across
  the fleet, one row each, with the repo as a column (PRs first, then issues,
  each linking to GitHub) and a per-fleet count. Open issues/PRs are folded into
  the audit payload (fetch_activity), so the dashboard stays a pure view.
• New housekeeper serve housecaptain.toml command: serves the dashboard from a
  local web server with a Regenerate button — and an optional 60s
  auto-refresh — that re-audits the fleet on demand. The static --html file
  output is untouched; the live controls are injected only into the served page.
• housekeeper fleet now audits members concurrently (a thread pool,
  results still in fleet order), so a full re-audit drops to about the slowest
  single repo instead of the sum — roughly 3× faster on the powderworks fleet.
• Dashboard legend spells out the glyphs — warn is now
  "recommended, not required" and fail is "required", with hover tooltips —
  so a ! cell reads as advisory rather than mysterious.