## What & why Brings the engineer-facing FDS documentation next to the code it describes. Imported from `projects/open-register-fd/` in `Respellion/innovation-lab` and translated to Dutch: **six ADRs**, the ADR index and template, the **L3 component view**, and the **slice-1 proposal**. The architecture blueprint, the FDS gap analysis and the two privacy views stay in the lab repo — the OKRs cite them and they feed tender responses. Each side names the split in a "Wat ligt waar" table, so nothing is documented twice. Closes #159 ### Why `docs/architecture/fds/` and not `docs/architecture/` This repo's own ADR series now runs `adr-0001-loose-coupling` … `adr-0010-bff-oidc`. The imported set is numbered 0001–0006, so a flat import would collide across the whole imported range. The subfolder preserves the imported numbering, and with it roughly thirty `ADR-000N` cross-references inside the imported text that would otherwise all need rewriting. In the MkDocs sidebar the imported six appear as **FDS ADR-000N** so they are not confused with this repo's series. `docs/architecture/fds/README.md` explains the two series. ### Mermaid support was missing `pymdownx.superfences` had no `custom_fences`, so the imported diagrams would have published to Gitea Pages as raw code blocks. This PR adds the mermaid custom fence, the nav group, and one link under *Where to go* in the docs index. ## Definition of Done - [x] Linked Gitea issue (above). - [ ] Failing test committed before the implementation. — n/a, documentation only. - [ ] Implementation makes the test pass. — n/a, documentation only. - [x] Conventional Commits referencing the issue (`refs #159`). - [x] Rebased on current `main`; no conflicts. - [ ] CI green — n/a for content; the docs verification is below. - [ ] `docker compose up` reaches green health checks. — n/a, no runtime change. - [x] Docs updated if behaviour, contracts, or operations changed. - [x] ADR added in `docs/architecture/` if a non-obvious decision was made. — six imported, plus the numbering decision recorded in the folder README. - [ ] Demo note in `docs/demo-script.md`. — n/a, nothing user-visible. ## Verification run - `mkdocs build` — clean. No missing-nav warning for any `architecture/fds/` entry. The two remaining warnings are pre-existing on `main` and untouched here: the set of pages absent from `nav`, and a broken link in `runbooks/ci.md` to `services/acl/stryker-config.json`. - Mermaid renders as a diagram, not a code block: `site/architecture/fds/c4-component-view/index.html` contains `class="mermaid"`. - All relative markdown links in the repo resolve. ## Notes for reviewers - **Language.** The imported documents are Dutch; this repo's own documents remain English. Deliberate, not an oversight — the lab repo standardised on Dutch and these pages moved with it. Translating the rest is a separate decision. - **Ownership.** This repo sits in the `eho/` namespace while it now holds the canonical FDS architecture decisions that tender answers point at. Worth deciding whether it should move to `Respellion/`. - **Scope drift, not fixed here.** The imported text is faithful to its source, so the slice-1 proposal and the ADRs assume NHR/KVK for slice 1, while the lab-side blueprint still uses BAG as its example register. The lab-side documents carry a banner about this; Blueprint v2 (slice 5) is where the diagrams get corrected. - **Companion PR:** `Respellion/innovation-lab` #34 holds the lab-side half of this split.Reviewed-on: #160