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.