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/translate/page.tsx

@@ -402,13 +402,14 @@ export default function TranslatePage() {
                       isPro={config.isPro}
                     />
 
-                    {config.isPro && (
-                      <GlossarySelector
-                        glossaryId={config.glossaryId}
-                        onChange={config.setGlossaryId}
-                        disabled={submit.isSubmitting}
-                      />
-                    )}
+                    <GlossarySelector
+                      sourceLang={config.sourceLang}
+                      targetLang={config.targetLang}
+                      isPro={config.isPro}
+                      glossaryId={config.glossaryId}
+                      onChange={config.setGlossaryId}
+                      disabled={submit.isSubmitting}
+                    />
 
                     {/* PDF mode selector */}
                     {isPdf && (