0018 — UI information architecture: vloot / domein / techniek

Status: Accepted, 2026-09-22. Implements 2026-09-22-drie-lagen-ciso. Supersedes 0017.

Context. Mark walked the shipped UI with Playwright for the audience it is actually built for — a CISO or security officer who wants to know where does my data live, how is my infrastructure put together, and what can I do about it — and found the layer he expects first does not exist. /ui/ answered a single domain (an input field plus "recent beantwoord"); the fleet screen managed domains but never totalled them; the aggregate fleet numbers a Tourist actually wants ("Sovereignty by flow — Hosting: all 3 in EEA") were buried 6.700 pixels down /ui/trends, dressed as a table header between two rule dumps.

0017 mapped Tourist to /ui/ (a target list), Explorer to the per-scan report, and Farmer to Trends (the rule catalogue + matrix, returned to over time). That mapping assumed /ui/ was already a fleet view. It became a single-domain answer page under 2026-09-20-answer-first-ui, and no fleet aggregate ever moved back to replace it — the persona-to-route assignment quietly went stale without anyone re-deciding it.

Decision. Re-derive the three surfaces from what each persona actually asks for, not from which route happened to hold that question before:

• De vloot (Tourist) — /ui/: one score for the whole fleet (x/n, unanswered apart), the count of domains that are not sovereign, the verdict-per-flow breakdown, and the fleet's most expensive rules. The scan input field stays, as an action on the page, not the page's reason to exist.
• Het domein (Farmer) — the answer page (/ui/scans/{id}/answer): the seven sovereignty questions for one domain, each with its ja/nee/onbekend verdict, the x/n score for that domain, and — for every point that is not sovereign — the concrete handeling to fix it. "How am I doing" and "what do I do about it" live on the same screen.
• De techniek (Explorer) — the onderbouwing (/ui/scans/{id}/assessment): the same seven questions restated as an answer sheet with evidence, and — one click further, not open by default — the two raw framework tables (DICTU + EU CSF/SEAL) with rule IDs, criteria, and per-rule rationale. The per-rule deep-dive (/ui/reporting/{fw}/{ruleID}) stays the floor beneath this layer.

The nav keeps its two tabs — Overzicht (/ui/, /ui/orgs/{slug}) and Trends (/ui/trends) — but they no longer carry the Tourist/Farmer labels 0017 gave them: Trends is a fleet-wide rule catalogue and score matrix an operator returns to, not a persona's home screen in this mapping. It is not retired — de-scoping Trends is explicitly out of scope for this change — but it no longer anchors the IA the way Overview did under 0017.

Consequences. No probe/assessor/store change; pure web-ui IA, same as 0017. /ui/ gains the fleet aggregate it never had (vlootscore, distribution, top-3 costly rules). The answer page gains an x/n score and remediation lines it did not carry under 0017. The onderbouwing page's frameworktabellen move behind a <details> so the seven questions are the page's first impression, not a stepping stone past two rule dumps. docs/explanation/adr/0017-ui-personas.md stays in the repo, marked superseded, for anyone tracing why an old PR referenced "Tourist = Overview".

Rendered surface

• De vloot (/ui/, /ui/orgs/{slug}) opens with the scan-input form as a compact bar under the header, then shows the fleet as pictures (change 2026-09-24-vloot-in-beeld, after Mark on 2026-09-24: "still too much Analysis"): the vlootscore as a ring with a legend (soeverein, niet soeverein, onbeantwoord), one stacked bar per stroom, the top-3 duurste regels as handelingen with a "x van n domeinen" bar, and the domains as a grid of domein × stroom (slechtste eerst). No rule rationale on this layer; it lives on the rule page, one layer down. Every picture carries its facts as text too.
• Het domein (/ui/scans/{id}/answer) shows the x/n score next to the oordeelzin, and one handeling per niet-soeverein flow.
• De techniek (/ui/scans/{id}/assessment) opens with the seven flow questions (section.sovereignty-overview); the two framework tables render inside <details class="framework-details">, closed by default, with a <summary> naming how many regels are underneath across how many frameworks.
• Trends (/ui/trends) is unchanged by this decision: rule catalogue + score matrix, still reachable from the nav.

Go tests cover the vlootscore build (internal/ui/fleet_score_test.go), the answer page's score + remediation (internal/ui/flow_answers_test.go, internal/ui/answer_test.go), and the onderbouwing page's collapsed framework tables (internal/ui/ui_test.go, TestAssessmentPage_FrameworkTablesCollapseBehindOneClick). Playwright coverage for the fleet score and the worst-domain-first ordering is tracked as run 05 task 6.1, not yet written as of this ADR.