* feat(themes): validate and extract locally imported theme packages
Add the backend + validation half of local theme import: users will be
able to load a theme packaged as a .zip (manifest.json + theme.css).
- `import_theme_zip` Tauri command unpacks only manifest.json + theme.css
from the archive, outside the webview, with an archive-size cap,
per-entry uncompressed caps, and path-traversal rejection.
- `validateThemePackage` runs the full theme-store contract in-app: the
manifest schema (field patterns copied from the repo schema), the CSS
token whitelist with all core tokens required, color-scheme matching
the declared mode, data-URI restricted to the arrow token, and a guard
against ids that collide with built-in themes. The existing
`validateThemeCss` containment guard is reused and runs again at
injection time. The contract token list is a byte-identical copy of the
themes repo's allowed-tokens.json.
Covered by validateThemePackage tests for every rejection class.
* feat(themes): add the Import a theme section to the Themes tab
A dedicated section between the theme scheduler and the Theme Store lets
users import a theme from a local .zip. After the package validates, a
confirmation dialog names the theme and its author before it is installed.
A rejected import shows a plain-language explanation aimed at end users;
the raw contract diagnostics (token names, missing fields) are tucked
into a collapsible "Technical details" block for theme authors. Fully
localised across all nine languages.
* docs(themes): changelog + credits for local theme import
Fold the local .zip import (and the store pagination / refresh-scroll
polish) into the still-unreleased Theme Store entry rather than a new
section, and extend the credits line. PRs #1011 and #1012.
Psychotoxical