✨ Advertise a post's translation on the post page

[ker0x]

What

A reader landing on an English post had no signal the French version existed short of hunting for the locale switcher. This renders a notice above the post content pointing at the translation, plus the supporting design-token and tooling work that came with it.

Changes

✨ Translation notice — the post page loops over the alternates the resolver already returns, filtered to locales other than the current one. An untranslated post yields an empty list, so the block disappears without a guard. The notice is written in the target language and carries a matching lang attribute, since it addresses a reader who does not necessarily read the current one.

Alert gains info/warning variants and a role prop — alert is for something that just went wrong, and a standing note is note.

🎨 Semantic colour tokens — templates reached for dark-cyan and golden-orange directly, naming the hue rather than the job. --info and --warning now point at those brand values and components ask for the role, so a palette change lands in app.css alone. --dark-cyan-soft follows as --info-soft.

💄 Syntax theme reset — highlight.css drops back to the palette tempest/highlight ships with, as the starting point for restyling the code surface against the new tokens.

📝 Markdown styleguide — checking prose styles after a design change meant hunting the archive for a post that happened to contain a table or a footnote. This renders every construct the parser understands on one page. It carries draft: true, so it lists locally and stays off production.

Testing

Three integration tests cover the notice: French advertised on an English post, English on a French post, and nothing at all on an untranslated one.

• ShowControllerTest — 15 tests, 46 assertions, green
• PHPStan level 8 — no errors
• Twig CS Fixer — 99 files, 0 notices
• Twig/YAML lint + Doctrine mapping — OK
• Tailwind build — --info-soft and the info/warning utilities emit correctly

Note for review

The syntax theme is a deliberate reset, not a finished design — code blocks currently sit on a hardcoded dark surface in both themes. Restyling it against the new tokens is follow-up work, and the styleguide post exists to make that easy to check.