[harness] Add the RCAC-Docs documentation factory (spec-driven authoring lifecycle)

[glentner]

Summary

Adapts the HyperShell spec-driven "software factory" to this documentation site, so agents can
shape → plan → author → review → ship documentation and training material with traceability and
human-gated review. Tooling only — no changes to published content. Everything lives outside
docs/, so nothing is added to the built site.

What's here

• Lifecycle skills (.agents/skills/docs-*): /docs-feature → /docs-plan → /docs-draft →
  /docs-review → /docs-publish (build renamed draft to avoid colliding with mkdocs build).
• Factory references (.agents/factory/): methodology.md, invariants.md, ears.md,
  style-guide.md, review-rubric.md, the getting-started.html onboarding page, templates/, and
  the FSM/strict_check scripts under bin/.
• Constitution: AGENTS.md rewritten as an operating manual + load-bearing invariants + a
  "working as an agent" section (CLAUDE.md symlinks it).
• Discovery wiring: .claude → .agents symlink (now git-tracked), narrowed .gitignore, and a
  least-privilege .agents/settings.json allowlist.
• CI: deploy_to_geddes_prod skips factory-only bookkeeping paths.

Key design decisions

• Verify by rendering: each phase's verify: runs mkdocs build --strict piped through
  strict_check.py, gating only on warnings not already in a captured baseline. (Prod CI builds
  with --verbose, so broken links / nav orphans ship silently today — the factory closes that gap.)
• Publish targets main — a merge auto-deploys to Geddes within ~5 min, so there is no staging
  gate and review is the last line of defense. dev (the a11y branch) is off-limits.
• hammerable: false for HPC technical accuracy, WCAG 2.1 content accessibility, and build
  integrity — the reviewer may never scope-cut them.
• Review splits CONFIRMED (machine-checked: build/links/nav/front-matter) from PLAUSIBLE
  (HPC accuracy / prose a11y → human triage).
• No Co-Authored-By trailer on commits (clean-log convention; §12 of AGENTS.md).

⚠️ Surfaced: 7 pre-existing broken links

Running mkdocs build --strict revealed 7 real broken internal links already on main (wrong
../ depth, a missing index.md, a doubled userguides/userguides/… path). They're recorded in
.agents/factory/strict-baseline.txt so the gate keys on regressions only. Not fixed here (2 are
in tool-generated catalog files) — an ideal first fix/ job for the factory to dogfood.

Verification

• FSM scripts byte-compile; next_phase/set_phase round-trip (dependency gating, canonical field
  order, body preserved verbatim).
• Strict gate passes with zero new warnings; .agents/ and spec/ are absent from site/.
• All five skill frontmatters validate; .claude symlink + factory are tracked while __pycache__
  and settings.local.json are ignored.

Try it

After merge (or checking out this branch) and reloading Claude Code so it discovers .claude/skills/,
start a job with /docs-feature. The full walkthrough is .agents/factory/getting-started.html
(open it in a browser) or .agents/factory/methodology.md.

Note

This is a substantial methodology addition intended to sit for human review before we test-drive it
across a few real use-cases and refine.

🤖 Generated with Claude Code

[glentner]

Broken links and --strict fixed by @Guangzhen-Jin out of band. Updates coming with first test-driven in next PR.