Check translation contracts offline, add Swedish to the installer and enable the website languages

- Offline checks for terminal and website catalogs reject translations that change commands, paths, identifiers or placeholders
- Terminal and documentation texts that broke those contracts are corrected in every language
- Swedish can be chosen in the stable and beta installers
- The website routes, language switcher and exported pages cover the eight languages, with the shared website texts in each of them
- Website documentation translations are generated only when requested
- From PR #475 by @jcastro

.github/workflows/test-i18n.yml

@@ -9,15 +9,20 @@ on:
       - 'AppImage/messages/**'
       - 'AppImage/lib/i18n/**'
       - 'AppImage/components/terminal-panel.tsx'
+      - 'web/**'
       - 'CONTRIBUTING.md'
       # Scheduler consumers and the offline extractor's .sh/.func inputs.
       - 'scripts/**/*.sh'
       - 'scripts/**/*.func'
       - 'scripts/**/*.py'
       - 'lang/*.json'
+      - 'menu'
+      - 'install_proxmenux.sh'
+      - 'install_proxmenux_beta.sh'
       - 'oci/src/**/*.py'
       - 'oci/catalog/**/*.json'
       - 'oci/remote/**/*.sh'
+      - 'oci/remote/**/*.py'
   push:
     branches: [main, develop]
     paths:
@@ -27,15 +32,20 @@ on:
       - 'AppImage/messages/**'
       - 'AppImage/lib/i18n/**'
       - 'AppImage/components/terminal-panel.tsx'
+      - 'web/**'
       - 'CONTRIBUTING.md'
       # Scheduler consumers and the offline extractor's .sh/.func inputs.
       - 'scripts/**/*.sh'
       - 'scripts/**/*.func'
       - 'scripts/**/*.py'
       - 'lang/*.json'
+      - 'menu'
+      - 'install_proxmenux.sh'
+      - 'install_proxmenux_beta.sh'
       - 'oci/src/**/*.py'
       - 'oci/catalog/**/*.json'
       - 'oci/remote/**/*.sh'
+      - 'oci/remote/**/*.py'
   workflow_dispatch:
 
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