Task 634: Add og:locale Meta Tag

Status: DONE

Problem

Missing og:locale Open Graph meta tag. Social sharing previews don't indicate the content language.

Solution

Added <meta property="og:locale" content="ja_JP"> to the HTML template. Added E2E test verifying the tag.

Files Modified

• ts/src/templates.ts — Added og:locale meta tag
• ts/e2e/reports.spec.ts — Added og:locale E2E test