fix: remove DeepSeek/MiniMax branding, fix glossary visibility, improve translate page UX

- US1: Replace exposed provider names (DeepSeek V3 → IA Express, MiniMax → IA Avancée)
  in legacy_routes.py, remove 52 DeepSeek references from i18n pricing/landing keys,
  add generic modelName key across all 13 languages
- US2: Fix glossary selector filtering (fallback to all glossaries when source lang
  filter returns empty), show templates by default, fix 3 broken presets
  (hvac/construction/automotive → hr/scientific/ecommerce)
- US3: Replace 15 hardcoded French strings with i18n t() calls, increase font sizes
  from 8-9px to 11px, improve text contrast (opacity /20→/40, /25→/45, /30→/50)
- US4: Add missing provider labels in admin ProviderStatus (deepseek, minimax, zai,
  google_cloud, openrouter, openrouter_premium)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/app/dashboard/translate/GlossarySelector.tsx

@@ -40,7 +40,7 @@ export function GlossarySelector({ sourceLang, targetLang, isPro, glossaryId, on
   const [importingId, setImportingId] = useState<string | null>(null);
   const [error, setError] = useState<string | null>(null);
   const [isOpen, setIsOpen] = useState(false);
-  const [showTemplates, setShowTemplates] = useState(false);
+  const [showTemplates, setShowTemplates] = useState(true);
   const containerRef = useRef<HTMLDivElement>(null);
 
   const fetchData = useCallback(async () => {
@@ -125,17 +125,20 @@ export function GlossarySelector({ sourceLang, targetLang, isPro, glossaryId, on
   const sourceFlag = SUPPORTED_LANGUAGES.find(l => l.code === sourceLang)?.flag ?? '';
   const targetFlag = SUPPORTED_LANGUAGES.find(l => l.code === targetLang)?.flag ?? '';
 
-  const filteredGlossaries = sourceLang === 'auto'
+  const langFiltered = sourceLang === 'auto'
     ? glossaries
     : glossaries.filter(g => g.source_language === sourceLang);
 
+  // If filtering by source language yields nothing, show all glossaries
+  const filteredGlossaries = langFiltered.length > 0 ? langFiltered : glossaries;
+
   const selected = glossaries.find(g => g.id === glossaryId);
 
   return (
     <div className="space-y-2 relative" ref={containerRef}>
-      <label className="text-[9px] font-black text-brand-dark/40 dark:text-white/40 uppercase tracking-[0.2em] block">
-        <BookText size={10} className="inline mr-1.5 text-brand-accent" />
-        {t('translate.glossary.title')} <span className="normal-case tracking-normal font-normal text-brand-dark/25 dark:text-white/25">({sourceFlag}→{targetFlag})</span>
+      <label className="text-[11px] font-black text-brand-dark/50 dark:text-white/50 uppercase tracking-[0.15em] block">
+        <BookText size={12} className="inline mr-1.5 text-brand-accent" />
+        {t('translate.glossary.title')} <span className="normal-case tracking-normal font-normal text-brand-dark/40 dark:text-white/40">({sourceFlag}→{targetFlag})</span>
       </label>
 
       {/* Dropdown trigger */}
@@ -158,12 +161,12 @@ export function GlossarySelector({ sourceLang, targetLang, isPro, glossaryId, on
             </div>
             <div className="min-w-0 flex-1">
               <div className="text-[11px] font-bold truncate text-brand-accent">{selected.name}</div>
-              <div className="text-[9px] text-brand-dark/30 dark:text-white/30">{selected.terms_count} {t('translate.glossary.terms')}</div>
+              <div className="text-[11px] text-brand-dark/50 dark:text-white/50">{selected.terms_count} {t('translate.glossary.terms')}</div>
             </div>
             <button
               type="button"
               onClick={(e) => { e.stopPropagation(); onChange(null); }}
-              className="shrink-0 w-5 h-5 rounded-full flex items-center justify-center text-brand-dark/20 hover:text-brand-dark hover:bg-brand-muted dark:text-white/20 dark:hover:text-white dark:hover:bg-white/10 transition-colors"
+              className="shrink-0 w-5 h-5 rounded-full flex items-center justify-center text-brand-dark/40 hover:text-brand-dark hover:bg-brand-muted dark:text-white/40 dark:hover:text-white dark:hover:bg-white/10 transition-colors"
             >
               <X size={11} />
             </button>
@@ -182,12 +185,12 @@ export function GlossarySelector({ sourceLang, targetLang, isPro, glossaryId, on
             </span>
           </>
         )}
-        <ChevronDown size={14} className={cn("shrink-0 text-brand-dark/20 dark:text-white/20 transition-transform", isOpen && "rotate-180")} />
+        <ChevronDown size={14} className={cn("shrink-0 text-brand-dark/40 dark:text-white/40 transition-transform", isOpen && "rotate-180")} />
       </button>
 
       {/* Error */}
       {error && (
-        <p className="text-[10px] text-red-500 pl-1">{error}</p>
+        <p className="text-[11px] text-red-500 pl-1">{error}</p>
       )}
 
       {/* Dropdown panel */}
@@ -221,7 +224,7 @@ export function GlossarySelector({ sourceLang, targetLang, isPro, glossaryId, on
                           {g.name}
                         </div>
                       </div>
-                      <span className="text-[9px] text-brand-dark/25 dark:text-white/25">{g.terms_count} {t('translate.glossary.terms')}</span>
+                      <span className="text-[10px] text-brand-dark/45 dark:text-white/45">{g.terms_count} {t('translate.glossary.terms')}</span>
                     </button>
                   );
                 })}