Bug-fix release.

Bug-fix release. Closes the structural rendering bug discovered 2026-05-15 in the auto-derived /releases/<version> path shipped in 1.9.0 (CR-46 consolidation). Each section's bullet items were pushed as separate elements of the parts array and joined with \n\n, so the blank lines between consecutive - foo markdown lines terminated each list — every bullet rendered as its own single-item <ul> instead of one <ul> per section. Affected all 17 auto-derived release pages on production (1.6.x, 1.5.x, 1.4.x, ...); MDX-override pages (1.5-to-1.6, 1.7.0, 1.8.0, 1.9.0) were unaffected. Bug was visually verified live pre-fix: /releases/1.6.3 had 4 headings + 21 single-item <ul> elements; /releases/1.5.7 had 3 headings + 8 single-item <ul> elements. Fix builds each section as one ### heading\n\n- a\n- b\n- c block; new RCC-05 drift-guard asserts bulletBlockCount === sectionCount for every auto-derived release, making the regression class structurally impossible.

Fixed

• website/src/lib/releases.ts:135-138 getReleaseContent() — replaced the per-bullet parts.push('- ' + item) loop with const bullets = sec.items.map(i => '- ' + i).join('\n'); parts.push('### ' + sec.heading + '\n\n' + bullets). Final parts.join('\n\n') now only inserts blank lines between sections, never between bullets within a section. Visual result post-fix: each section renders as one <ul> with N <li> children (correct markdown semantics + correct accessibility tree + correct keyboard navigation).

Added

• website/src/tests/releases-changelog-coverage.test.ts RCC-05 — drift-guard asserting content.split(/\n{2,}/).filter(b => b.trim().startsWith('- ')).length === entry.sections.filter(s => s.items.length > 0).length for every source==='changelog' release. Also asserts every line inside a bullet block starts with - (no contaminating prose). Structural drift-prevention per CR-46 — the regression class cannot reappear without test failure.

Verification

• cd website && npx vitest run releases-changelog-coverage.test.ts — 5/5 pass (incl. new RCC-05 against all 17 auto-derived releases).
• cd website && npx tsc --noEmit — 0 errors.
• cd website && npm test — 323/323 pass (baseline preserved).
• Pre-fix live evidence: /releases/1.6.3 → 21 single-item <ul>s; /releases/1.5.7 → 8 single-item <ul>s. Post-fix shape verified at the markdown layer via RCC-05 invariant.