v1.21.0

What's Changed

• chore(render): gate raster-only helpers behind png/pdf; sync internal dep versions by @keroway in #493
• chore(deps): bump actions/checkout from 6 to 7 by @dependabot[bot] in #494
• chore(deps): bump getrandom from 0.4.2 to 0.4.3 by @dependabot[bot] in #495
• 実装全体レビューの修正: User-Agent / ドキュメント同期 / map 警告 (#496, #497, #498) by @keroway in #499
• feat: refresh WebUI gallery templates by @keroway in #506
• feat(rendering): JsRenderOptions に lane 行高 / 縦密度オプションを追加 (#507) by @keroway in #508
• chore: align formatter tooling to prevent pi-lens format drift by @keroway in #509
• chore: align rustfmt style edition by @keroway in #511
• chore(security): fix non-breaking npm audit findings in webui by @keroway in #512
• chore: release v1.21.0 by @keroway in #514

Full Changelog: v1.20.0...v1.21.0