feat: present Arxiv Discovery as a native macOS app

[Gnaroshi]

Summary

• update Arxiv Discovery facts and independent EN/KO copy for the native SwiftUI macOS application
• publish the owner-approved 1946 × 1480 native window capture with deterministic demo disclosure
• retire the four Flask-era Arxiv Discovery assets from the current public register
• restore the paired featured-application media layout and keep desktop/mobile card rows aligned
• retain the scenario disclosure when the single approved image is already used as primary evidence
• add SHOWCASE_APPLICATION_ID for bounded regeneration when only one application source is available locally

Cross-repository source

• application PR: feat: replace Flask UI with native macOS Arxiv Discovery Arxiv-newest-paper-crawler#4
• approved capture baseline: 1f87f235e2bef334980c19e019c016bb2a60ef0c
• installed delivery head: 48de418155624134e5f79efdee2e7ba17852e167
• bundle identifier: dev.gnaroshi.ArxivDiscovery
• installed native delivery: version 0.3.0, build 26
• website head: 08c7be1

Evidence boundary

The published image contains three deterministic demo paper candidates, visibly identifies showcase mode, and disables network requests, translation, and downloads. It contains no personal reading activity, credentials, private path, or repository data. The retired Flask captures remain historical only.

Verification

• npm run content:check
• npm run check
• npm run build
• npm run check:i18n
• npm run check:public-tone
• npm run check:launch-content
• npm run check:links
• npm run media:check — 21 approved screenshots
• npm run check:project-readiness — 8 projects, 21 approved screenshots
• npm run check:project-copy
• npm run test:smoke — 5 passed
• npm run test:feed-contract — passed with the canonical local contract
• npm run test:e2e — 152 passed
• npm run test:a11y — 55 passed
• project visual matrix — desktop 1440 dark and mobile 390 dark passed
• manual EN/KO desktop and mobile visual review passed

The first feed-contract attempt omitted CONTENT_FEED_CONTRACT_PATH and the first canonical rebuild encountered a transient Astro prerender artifact lookup. Both were rerun with the correct contract path and completed successfully.