fix(rpubs): fix flipbook white screen and align flow with /press landing
- Flipbook: wrap async initFlipbook in try-catch with scroll fallback,
add 500ms verification timeout for silent StPageFlip failures, quote
data URLs in background-image, expand shadow DOM CSS coverage
- Flow: rename steps Create/Preview/Publish → Write/Press/Print to
match rpubs.online/press landing page description
- Routes: add /press editor route, bump script cache to v=3
- Publish panel: fix getEditorContent() reading from cached content
instead of missing textarea (not rendered during print step)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>