fix: keep D-30 answers in the first viewport

[fomin-dima]

Context

A live owner-acceptance preflight on beta commit 9ca6150 found that four of five prepared D-30 answer blocks started below the 1440x900 first viewport at y=904-999 px. The previous route budget covered the evidence index but not the five prepared question routes.

Correction

• scope a compact intro layout only to prepared answer pages;
• add all five prepared routes to fail-closed route budgets;
• measure RU/EN/ES/ZH at 1440x900 and 390x844;
• add browser regression coverage for first viewport, horizontal reflow, limitations and continuation;
• add no-JS coverage for all five answers and public source paths;
• record the live finding and correction evidence.

Evidence

• exact head: e69ec68
• local npm run check: PASS in 652.8 s
• Vitest: 140/140
• Playwright: 50/50
• prepared route budgets: 40/40
• maximum primaryTop: 500.27 px desktop, 478.47 px mobile
• maximum Tab count after skip link: 1
• production build, deterministic artifacts, links, schemas, privacy/policy and 10x scale: PASS

Boundaries

Public data, v3 tag/checksums, resolver semantics and scientific claims are unchanged. This PR does not mark the UI accepted or stable. A separate owner permission is required before merge and another live Pages preflight is required before D-48/D-49 review.

[fomin-dima]

Exact-head correction evidence

• Head: e69ec68
• Local npm run check: SUCCESS in 652.8 s
• Vitest: 140/140
• Playwright: 50/50
• Prepared D-30 budget cases: 40/40 across RU/EN/ES/ZH and desktop/mobile
• Maximum primaryTop: 500.27 px desktop, 478.47 px mobile
• Maximum Tab count after skip link: 1
• Push run 31444384078: Ubuntu SUCCESS, Windows SUCCESS
• PR run 31444405979: Ubuntu SUCCESS, Windows SUCCESS
• Final PR state: CLEAN / MERGEABLE

The currently deployed beta still uses 9ca6150 and retains the live first-viewport issue. This PR has not been merged and Pages has not been redeployed. Separate owner permission is required for both operations.

[fomin-dima]

Pages correction deployment evidence — 2026-08-11

• PR fix: keep D-30 answers in the first viewport #27 merged as 7f6328c.
• Pages workflow 31489493362: build SUCCESS in 8m51s; deploy SUCCESS in 40s.
• GitHub deployment 5850166667: github-pages state success.
• Live portal-build.json: UI 3.1.0-beta.1, beta/not_accepted, data 3.0.0+20260808, exact source commit 7f6328c.

Live D-30 owner preflight: 5/5 PASS on 1440x900, 390x844 and with JavaScript disabled.

• development-history: desktop y=500, mobile y=447, 8 source links;
• component-state: desktop y=500, mobile y=478, 10 source links;
• methods-publications: desktop y=500, mobile y=478, 10 source links;
• people-groups: desktop y=437, mobile y=478, 10 source links;
• open-work: desktop y=437, mobile y=447, 10 source links.

All flows had zero mobile horizontal overflow, visible limitations, correct destinations, stable EN locale routes and identical public source paths without JavaScript.

The technical preflight blocker is closed. Classification remains beta/not_accepted until signed D-48/D-49 owner review; component state remains fail-closed unknown until an external allowlisted component_version_contexts package is received.