[ShutenOishi]

Scope

Stage Japanese translations of the exact future verified Catalog descriptions and Test Contract scenarios of pgTAP, pg_variables and pg_store_plans. The existing /ja/ and /en/ routes, per-language switch and actual Catalog index-driven download rendering remain unchanged.

• Localize the three independently prepared English descriptions and three PG14–18 Test Contract v2 functional scenario descriptions.
• Preserve English originals on the /en/ route.
• Add native Node i18n tests for all six new strings and a guard against fabricated public release download URLs.
• No Catalog data, index entries, public downloads, SHA-256 claims, Release links, or signing status are introduced.

Upstream immutable source pins and Windows CI evidence: pgextwin/build#141 (comment).
Catalog verifier-first intake: pgextwin/catalog#133.

Safety

Wave3 three formal releases are unpublished and Issue #75 GO B/G4/G5 NO-GO; this is localization-only preparation. Existing protected lifecycle-tests App15368 must pass before squash merge and postmerge.