Strip docs/claude/ + sidebar entry once hydra.conduction.nl is live #66

Follow-up to the docs consolidation pass (PRs #15, #32, #9, #60, #65 merged; #64 open).

Phase 3 of the consolidation moved docs/claude/ content to the hydra repo (see hydra #273) and stood up hydra.conduction.nl. Once that site is verified live (DNS + GitHub Pages setup on the hydra side — tracked separately), this repo can stop carrying the duplicate.

Tasks

• Verify hydra.conduction.nl serves the using-claude/ section
• git rm -r docs/claude/ (28 files — README, getting-started, walkthrough, agents.md, workflow, app-lifecycle, commands(.md|-openspec.md|-tender.md), workstation-setup, global-claude-settings, docker, playwright-setup, local-llm, examples/{.mcp.json.example, CLAUDE.local.md.example}, frontend-standards, parallel-agents, retrofit, testing, writing-{specs,adrs,skills,docs}, skill-{checklist,patterns,evals}, rad-platform, img/mcp-servers-connected.png)
• Update website/sidebars.js: remove the { type: 'autogenerated', dirName: 'claude' } block and the Claude workflow category wrapper
• Update website/docusaurus.config.js navbar: change the /claude/ entry to https://hydra.conduction.nl/using-claude/ (external href)
• Update website/docusaurus.config.js footer: same change for the Claude workflow item under the Documentation column
• Optionally drop docs/hydra/README.md (it's a stub pointing at the hydra repo; could become a navbar-only external link instead)
• Verify the build still passes (cd website && npm run ci) with no new broken-link warnings

Why

The 28 docs/claude/ pages live in two repos right now (here + hydra's docs/using-claude/), which is the kind of double-documentation the consolidation pass is removing. Hydra is the right home — usage of Claude Code is fundamentally about the Hydra pipeline, not an org-wide engineering concern like docs/WayOfWork/ or docs/iso/.

Out of scope

• Adding NL translations to the engineering docs that stay here (WayOfWork/, iso/, ROADMAP, development-environment, archive) — incremental content task per the i18n/nl/ skeleton added in chore(website): bump preset to ^2.6.1 + add i18n/nl skeleton #65.