feat: add commit diff i18n, redesign blame view, bump v2026.4.304}
- Add i18n translation keys for commit diff labels (diff_lines, diff_type, diff_type_binary, diff_type_text, diff, diff_old, diff_new) across all 29 language files - Internationalize commit diff view: replace hardcoded "Old"/"New" labels in web worker with translated strings passed from commit.js - Internationalize commit.twig: replace hardcoded "Diff lines", "Type", "binary/text", and "Diff" button text with translation keys - Redesign blame view template (blame.twig) with flexbox-based layout, line numbers, alternating row backgrounds, and card container - Add new SCSS styles for blame view (.p3x-gitlist-blame-container, -row, -hash, -line-num, -content, -code) with dark/light theme support - Update Gruntfile.js sass-dev watcher to cover all src files and enable livereload on port 35729 - Add livereload script injection to layout.tpl.twig for dev workflow - Expose livereload port 35729 in docker-compose.yml - Bump version to 2026.4.304 and update CSS hash across themes.js and package.json - Bump build version references to v2026.4.303 in docs and markdown files