refactor: redesign book detail page to match journal mockup styling
- Replace Pico CSS with index-style custom CSS variables
- Redesign layout: back breadcrumb, info table, shelf/status selects
- Update spine-book-model: add shelf_name, format_icon/label, tags_display,
date display fields, rating display, status/shelf options
- Remove unused fields: meta, progress_label, formats array
- Update spine-book-model-test.el: 23 tests cover all new fields
- Add --text-danger CSS variable for remove button
jbrechtel
ca03e87a46