Complete full-corpus documentation parity and localization

[AndrewKirkovski]

Summary

• Completes documentation parity and natural localization across English, German, Spanish, Japanese, Korean, and Portuguese.
• Synchronizes runtime contracts, code examples, navigation manifests, local links and anchors, and frontend diagrams with the canonical English corpus.
• Preserves canonical fenced code and generated contract evidence while localizing human-facing prose and table labels.

Verification

• 179 reviewed pages per locale; each locale manifest contains 180 unique canonical paths in the same order.
• 1,989 fenced blocks and 2 generated contract regions per locale match canonical English exactly.
• Renderer-aware local links and anchors resolve; each locale has all 10 frontend SVG assets.
• Strict UTF-8 without BOM, structure/table/callout parity, frontend documentation checker, and Git diff integrity pass.
• Three independent final review rounds report EN, DE, ES, JA, KO, and PT clean at commit 3acbfa2.

Scope

• Locale onboarding pages at */start/about.md are intentionally unchanged.

[wolfy-j]

Merge review at 1d3e73b43e28cadf04b71743810abfbaf931bc8a: holding this PR because the current tree no longer satisfies its stated parity checks.

• English's manifest has 181 paths, all unique. DE/ES/JA/KO each have 218 entries but only 181 unique paths; PT has 222 entries but only 181 unique paths. These are duplicate navigation entries, not missing English pages.
• Comparing fenced blocks for the canonical manifest pages (excluding start/about) finds differences on 88 DE, 85 ES, 84 JA, 84 KO and 88 PT pages. This is not merely translated prose: for example, de/frontend/micro-frontends/quickstart.md omits the package.json version present in English and retains outdated prerequisites and example repository branch links.
• node scripts/check-markdown-links.mjs passes: 6,591 local Markdown links across 1,448 pages. node scripts/check-frontend-docs.mjs and git diff --check also pass, but those checks do not establish cross-locale navigation/example parity.

The main merge needs a locale parity pass, and the PR description's 180-path/1,989-fence claims need refreshing against the final tree. No review re-request is needed after polishing, but the parity failures must be resolved before merging.