Preserve document language during crossing data updates

[sbc1-code]

Crossing metadata effects clean up when fresh data or delayed aggregates arrive. That cleanup forced html.lang to English even while the page displayed Spanish. A fresh rendered baseline reproduced the mismatch on San Ysidro.

Preserve document language during metadata cleanup. Layout owns the selected language on shared routes; fixed-language article, methodology and privacy routes own their content language. Existing canonicals, route alternates, real EN/ES blog pairs and page data remain intact.

Validation:

• Regression fails on the previous English reset; all 10 metadata unit tests pass with the fix.
• Local desktop/mobile checks pass with mocked data and all external providers/service workers blocked: delayed aggregates, feed refresh, EN/ES switching, Back/Forward, home/blog/best-time navigation, and fixed-language routes with conflicting UI preferences.
• Independent reviewer approved the final diff after fixing wait-history fixture isolation.
• Complete build and npm test passed on exact-head push and PR runs: 215 static pages plus desktop/mobile route and language checks. Exact publication verification follows the gated merge.

Preserves PR128 timestamps and shipped PR129/130 hreflang checks. Fluctuating walk-or-drive inventory remains a separate prioritized roadmap item. No privacy text, credentials, provider settings or deployment configuration changed.

[sbc1-code]

Independent read-only review approved final commit c137067 with no remaining blocking findings. The reviewer’s wait-history isolation finding was fixed and the focused desktop/mobile fixture reran successfully.

Complete build and npm test passed on both exact-head runs:

• https://github.com/sbc1-code/borderpulse/actions/runs/38429942157
• https://github.com/sbc1-code/borderpulse/actions/runs/38429985292

CI verified 215 generated pages’ exact canonicals/hreflangs and reciprocal targets, desktop/mobile document-language checks (delayed aggregates, feed refresh, EN/ES switching, Back/Forward, shared/content-owned pages), and existing SPA hreflang/comparison navigation gates. Provider requests stayed blocked/mocked. Publication and exact production manifest/assets/metadata verification follow the gated merge.

[sbc1-code]

Publication and live verification complete.

• Merged source: 3c010b6. Prior PR128 timestamp and PR129/130 hreflang commits remain ancestors.
• Automatic production workflow succeeded: https://github.com/sbc1-code/borderpulse/actions/runs/38430512731. Full build/npm test passed against production settings, including 214 generated pages and desktop/mobile document-language + SPA hreflang fixtures. Inventory differs from PR CI because main contains a newer data snapshot; walk-or-drive capability inventory remains a separate roadmap item.
• Vercel deployment dpl_8DSFbtx9WzikqJ87bHYL7RuocGfD is READY with borderpulse.com/www aliases, source 3c010b6.
• Public publication.json matches exactly: prepared_at 2026-10-13T16:26:56.821Z, CBP snapshot 2026-10-13T16:22:35.285Z, 42 crossings.
• Read-only production HTTP checks passed for 46 pages: exact canonicals and route alternates, all 36 published blog language pages and reciprocal targets. Fixed article/methodology/privacy document languages also passed.
• All 24 served JS/CSS assets match the local production-setting build SHA256 byte for byte. Runtime behavior was checked on that application locally and again against the actual production-settings artifact in CI; live verification executes no ads/analytics scripts.

No publication blocker remains. No ranking improvement is claimed. Evidence retained in the delegated local workspace as evidence/document-language-production-20261013.json and the complete CI logs.