Adds a new top-level Automation nav group with seven pages covering the
end-to-end issue->mergeable-PR pipeline that spans three repos:

- automation/overview — the three-layer pipeline (cloud GHA, cron
  routines, local /ship) with a canonical end-to-end diagram
- automation/issue-to-pr-pipeline — the eight-step cloud flow on this
  repo, with which trigger fires which caller and what each does
- automation/ai-workflows — catalog of the 16 reusable workflows in
  JacobPEvans/ai-workflows: event-triggered, scheduled, and what's
  deprecated or disabled
- automation/claude-code-routines — the six cron-scheduled cloud
  routines: morning briefing, sentinel, custodian, issue solver, daily
  polish, weekly scorecard; the deploy-routines GHA workaround
- automation/ship-and-finalize — /ship + /finalize-pr lifecycle with
  the canonical five-phase diagram and the known reliability gaps
  being closed in a follow-up against claude-code-plugins
- automation/codeql-resolution — why CodeQL is fixed separately from
  CI checks, and how /resolve-codeql plugs into /finalize-pr Phase 2
- automation/shape-issues — the /shape-issues local skill and how it
  feeds well-scoped issues into the resolver pipeline

Cross-links from existing pages:
- architecture/ai-pipeline.mdx -> /automation/overview (mechanics)
- tools/automation.mdx -> /automation/overview + /automation/ship-and-finalize
- ai-development/claude-code-plugins.mdx -> /automation/ship-and-finalize
  + replaces direct GitHub links with /automation/* internal links for
  claude-code-routines and ai-workflows

All new diagrams use the canonical hand-drawn Reef Green theme directive
byte-for-byte; grep validates one unique directive across the site.
Word counts within tier caps (tier 1 <=450, tier 2 <=900). All internal
links validated by mint broken-links.

Assisted-by: Claude <noreply@anthropic.com>

… add nix-claude-code

Restructure the Automation group for future growth:

- automation/cloud-pipelines/  (NEW subdir) — ai-workflows lives here now
- automation/scheduled-routines/  (NEW subdir) — claude-code-routines lives here
- ai-development/skills/  (NEW subdir) — ship-and-finalize, codeql-resolution moved
  out of automation/ since they are local Claude skills, not pipeline plumbing
- nix/nix-claude-code  (NEW page) — declarative Claude Code via home-manager,
  the missing piece between the binary (nix-ai) and the install (this)
- automation/shape-issues  DELETED — /shape-issues is not actually used; Claude
  plan mode covers the same workflow

Each new subdirectory carries its own overview.mdx as a landing page. The
top-level automation/overview now points at three pillars (Cloud pipelines,
Scheduled routines, Skills) instead of a flat seven-card grid.

Also scrub the Claude Max plan / $200/month pricing line in ai-workflows.mdx
(replaced with "included monthly automation credits on the Claude subscription
that backs these workflows"), and codify the cost-and-tier reporting rule in
security/scrubbed-values.mdx:
- Never name a specific AI subscription tier in committed content
- Cost figures are monthly with the per-instance × instances/month math visible
- Schedules and rate limits are not costs and stay as-is

Also fix two stale agentsmd/rules/* references that were broken by the prior
rules-migration PR:
- automation/cloud-pipelines/ai-workflows.mdx: ci-cd-policy.md link now points
  at /infrastructure/cicd/policy
- automation/issue-to-pr-pipeline.mdx: git-signing.md link now points at
  /infrastructure/cicd/git-signing

27 internal links audited; all resolve. JSON valid. Mermaid theme directive
remains the single canonical form across the site.

Assisted-by: Claude <noreply@anthropic.com>

The section listed marketing tiers (Claude Max, ChatGPT Pro, Copilot
Business) by name as a forbidden list, which made the public docs site
the public memorial of a behavioral rule that belongs in agent context,
not on a docs page.

The underlying behavior — no specific pricing or tier names in committed
content — stays as agent guidance.

Assisted-by: Claude <noreply@anthropic.com>