Replace all hardcoded English strings in three HTML Jinja2 templates with
`{{ _("key") }}` translation function calls, adding 87 new keys to en.json.
files.html:
- Page title, drop overlay, upload modal, error messages
- All filter labels, placeholders, options (status, OCR quality, etc.)
- Saved searches and full-text search UI
- Bulk action buttons, table headers, pagination
- Delete and preview modal text
settings.html:
- Page heading, configuration priority legend
- Header buttons (Wizard, DB Wizard, Export, Audit Log)
- Search bar placeholder and aria-labels
- Sidebar categories, no-results state
- Per-setting labels: required, enable prefix, effective value
- Autocomplete and model picker hints/placeholders
- Revert/save button labels and states
pipelines.html:
- Page title and subtitle
- New Pipeline button, loading state, empty state
- Pipeline card badges (System, Default, Inactive, Disabled)
- Add/Edit step modal fields and labels
- OCR language options and hints
- Cancel/Delete buttons in all modals
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
- Create i18n utility module (app/utils/i18n.py) with translation loading,
browser language detection, AI fallback, and l10n helpers
- Add JSON translation files for EN, DE, FR, ES, IT, PT, NL, PL, ZH, RU
- Add preferred_language column to UserProfile model with migration
- Register _() translation function as Jinja2 global
- Update base.html with translated navigation, footer, cookie notice
- Add language selector dropdown in nav bar (desktop + mobile)
- Create API endpoints for language preference (POST/GET /api/i18n/)
- Support language detection: user profile > cookie > Accept-Language > default
Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>