docs(skills): extract house recipes as Claude Code skills for SSP templating

8 template-generic skills in .claude/skills/ (new-feature, new-context,
value-object, form-machine, bff-endpoint, mutation-command, ui-component,
new-ssp), condensed from CLAUDE.md/ARCHITECTURE/fp-tea/ADRs and pointing at
this repo's worked examples. CLAUDE.md gains a pointer.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.claude/skills/new-ssp/SKILL.md

@@ -0,0 +1,55 @@
+---
+name: new-ssp
+description: Bootstrap a new self-service portal from this repo as a template — what to keep, strip, rename, and re-seed. Use when starting a new SSP for a different domain/register.
+---
+
+# New SSP from this template
+
+The template's value is the **enforced architecture** (layer fences, token gate,
+a11y gate, API-drift gate) and the shared building blocks — not the BIG-register
+business content. Keep the machinery, replace the domain.
+
+## Keep as-is
+
+- `src/app/shared/` — kernel (`fp.ts`), application (`remote-data`, `store`,
+  `submit`), ui atoms/molecules, layout templates, upload subtree.
+- Tooling: `eslint.config.mjs`, `scripts/check-tokens.sh`, `.github/workflows/ci.yml`,
+  `nswag.json`, `.storybook/`, `proxy.conf.json`, `.npmrc` (`legacy-peer-deps` —
+  and never `npm audit fix --force`, it downgrades Angular).
+- `src/app/auth/` (fake auth shell) and `src/app/shared/infrastructure/scenario.interceptor.ts` (dev-only).
+- `docs/architecture/` ADRs 0001–0003 — the decisions still apply; amend, don't delete.
+- `CLAUDE.md`, `docs/ARCHITECTURE.md`, `docs/fp-tea-atomic-design.md` — update names/examples as contexts change.
+- `.claude/skills/` — these recipes are the point of the template.
+
+## Strip / replace
+
+- Business contexts `registratie/`, `herregistratie/`, `brief/`, and `showcase/`:
+  delete or keep one slice temporarily as the worked example while building the
+  first real context (**new-context** + **new-feature** skills). If deleted, update
+  the worked-example paths in these skills to the new flagship context.
+- `app.routes.ts` routes and `tsconfig.json` aliases for removed contexts, plus
+  their eslint blocks in `eslint.config.mjs`.
+- Backend: keep the skeleton (`Program.cs` minimal-API style, ProblemDetails 422,
+  `X-Correlation-Id` audit line, `/api/v1` versioning, `Contracts/`/`Domain/`/`Data/`
+  split, test project) — replace `Data/SeedData.cs`, `Domain/*` rules, and
+  `Contracts/*` DTOs with the new domain's. Rename the solution/projects from
+  `BigRegister.*` (also update `package.json` `gen:api` and `ci.yml` paths).
+- Regenerate the seam: `npm run gen:api` (commits `backend/swagger.json` +
+  `src/app/shared/infrastructure/api-client.ts`).
+- Branding: `public/cibg-huisstijl/` + the token bridge in `src/styles.scss` — for a
+  different house style, swap the vendored CSS and re-point the `--rhc-*` bridge
+  (ADR-0003 pattern: bridge, don't rewrite tokens).
+- `docs/backlog/` WPs, PRDs, and memory-specific docs — new portal, new backlog
+  (keep `docs/backlog/README.md`'s WP process/template if you like the workflow).
+
+## Verify — the GREEN gate must pass at every step
+
+```bash
+npm run lint && npm run check:tokens && npm test && npm run build
+npm run build-storybook && npm run test-storybook:ci
+cd backend && dotnet test && cd ..
+npm run gen:api && git diff --exit-code backend/swagger.json src/app/shared/infrastructure/api-client.ts
+```
+
+Strip incrementally and keep this green — the fences are only worth having if they
+never go red.