feat: multilingual glossary templates + inline GlossarySelector rewrite

- Enriched 8 glossary templates with 18,191 translations across 11 languages
  using LLM batch generation + back-translation validation (99.98% confirmed)
- Rewrote GlossarySelector as inline section with template creation
- Fixed sidebar duplicate (single Glossaries link with proOnly flag)
- Added glossaryId reset when sourceLang changes
- Always show GlossarySelector (locked with Pro badge for free users)
- Added source_language flag on glossary cards
- Redirected /dashboard/context to /dashboard/glossaries
- Updated import endpoint to read translations from templates
- Added enrichment script (scripts/enrich_glossary_templates.py)
- Added 6 i18n keys across all 13 locales

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

routes/glossary_routes.py

@@ -600,6 +600,7 @@ async def import_glossary_template(
                     glossary=glossary,
                     source=term_data.get("source", ""),
                     target=term_data.get("target", ""),
+                    translations=term_data.get("translations") or None,
                     created_at=datetime.now(timezone.utc),
                 )
                 session.add(term)