[gnacho]

Brings landing/ in line with what is already deployed at https://scribe.cloudless.club.

The site was updated straight on the server, so the repository still carried the version from #150. A deploy from a clean clone would have silently reverted the Flathub tab.

What changed

• Flathub tab in the install section, selected by default, with flatpak install flathub io.github.gnacho.Scribe and flatpak run io.github.gnacho.Scribe.
• A "Disponible en Flathub" link next to the hero actions, and installUrl plus sameAs for Flathub in the JSON-LD.
• Every install tab now carries its own link instead of the single hardcoded GitHub one: the formats table in main.js gained link, linkText and linkTextEn, and updateInstall() rewrites the href and label. Flathub goes to the listing, AUR to the AUR package and deb, rpm and AppImage to the latest release.
• Cache-busting marker advanced to ?v=20261027a for the CSS, main.js and the i18n.js import.
• Also includes the adjustments that were live but never committed: the hero demo markup and its script, the install footer with the copy button next to the download link, the proof strip with the privacy line, the removal of the version badge and the updated styles.
• New i18n keys: "Disponible en Flathub", "Ver en Flathub", "Ver en AUR" and "Descargar desde GitHub".

Notes

No new deploy is needed: every file in landing/ after this PR is byte for byte what the server is serving, which is how it was verified (fetching the live HTML, main.js, i18n.js, style.css and fonts.css and diffing them against the working tree).