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>

frontend/src/app/dashboard/glossaries/page.tsx

@@ -16,6 +16,7 @@ import { CreateGlossaryDialog } from './CreateGlossaryDialog';
 import { EditGlossaryDialog } from './EditGlossaryDialog';
 import { DeleteGlossaryDialog } from './DeleteGlossaryDialog';
 import { useToast } from '@/components/ui/toast';
+import { SUPPORTED_LANGUAGES } from './types';
 import { useTranslationStore } from '@/lib/store';
 import { API_BASE } from '@/lib/config';
 
@@ -353,6 +354,9 @@ export default function GlossariesPage() {
                 <h3 className="text-2xl font-black uppercase tracking-tight mb-2 text-brand-dark dark:text-white truncate">
                   {glossary.name}
                 </h3>
+                <p className="text-[10px] text-brand-dark/30 dark:text-white/30 font-bold uppercase tracking-widest mb-4">
+                  {SUPPORTED_LANGUAGES.find(l => l.code === glossary.source_language)?.flag ?? ''} {SUPPORTED_LANGUAGES.find(l => l.code === glossary.source_language)?.label ?? glossary.source_language}
+                </p>
                 <div className="flex justify-between items-center pt-8 border-t border-black/5 dark:border-white/10">
                   <span className="text-[9px] text-brand-dark/30 dark:text-white/30 font-black uppercase tracking-widest flex items-center gap-1.5">
                     <Hash size={10} />