style: remove premium labels + fix LU badge

- Remove all visible "premium" text labels across the app:
  Navigation sidebar: "Premium Audio" → "Your audio space"
  Header: "Premium Member" → "Membre"
  Login page badge: "Expérience Audio Premium" → "Votre espace audio"
  Dashboard hero badge: "Podcastic Premium" → "Podcastic"
  EpisodeCard fallback author: "Artiste Premium" → empty string

- LU badge: remove Check icon (was rendering as "?" in some envs),
  now shows clean "LU" text only

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/components/EpisodeCard.tsx

@@ -1,6 +1,6 @@
 import React from 'react';
 import { Episode } from '../services/episodeService';
-import { Play, Pause, Calendar, Activity, Check, CheckCircle2, Circle } from 'lucide-react';
+import { Play, Pause, Calendar, Activity, CheckCircle2, Circle } from 'lucide-react';
 import { useAudio } from '../context/AudioContext';
 
 interface EpisodeCardProps {
@@ -75,7 +75,6 @@ export default function EpisodeCard({ episode, onPlay, onDetails, onToggleRead }
         <div className="absolute top-3 left-3 flex items-center gap-2 z-10">
           {isCompleted && (
             <div className="px-2.5 py-1 rounded-lg bg-emerald-500/90 backdrop-blur-md border border-emerald-300/30 text-[9px] font-black text-white uppercase tracking-widest flex items-center gap-1 shadow-lg">
-              <Check className="w-3 h-3" />
               LU
             </div>
           )}
@@ -112,7 +111,7 @@ export default function EpisodeCard({ episode, onPlay, onDetails, onToggleRead }
       <div className="flex-1 flex flex-col">
         <div className="flex items-center gap-2 mb-2">
            <span className="text-[9px] font-black text-[var(--accent-primary)] uppercase tracking-[0.2em] truncate flex-1">
-             {podcast?.author || 'Artiste Premium'}
+             {podcast?.author || ''}
            </span>
         </div>
         

frontend/src/components/Header.tsx

@@ -40,7 +40,7 @@ export default function Header({ title, subtitle, user, onLogout }: HeaderProps)
             <div className="flex items-center gap-4 sm:gap-6">
                <div className="hidden sm:flex flex-col items-end">
                   <span className="text-sm font-bold tracking-wide">{user.username}</span>
-                  <span className="text-[10px] font-medium text-[var(--text-secondary)] uppercase tracking-widest">Premium Member</span>
+                  <span className="text-[10px] font-medium text-[var(--text-secondary)] uppercase tracking-widest">Membre</span>
                </div>
                <div className="relative group/profile">
                   <div className="w-12 h-12 rounded-2xl p-[1px] bg-gradient-to-tr from-[var(--accent-primary)] to-[var(--accent-secondary)] transition-all">

frontend/src/components/Navigation.tsx

@@ -26,7 +26,7 @@ export default function Navigation() {
           </div>
           <div className="flex flex-col">
             <span className="text-xl font-display font-extrabold tracking-tight">PODCASTIC</span>
-            <span className="text-[10px] text-[var(--text-secondary)] font-bold uppercase tracking-[0.2em]">Premium Audio</span>
+            <span className="text-[10px] text-[var(--text-secondary)] font-bold uppercase tracking-[0.2em]">Your audio space</span>
           </div>
         </Link>
 

frontend/src/pages/Dashboard.tsx

@@ -163,7 +163,7 @@ export default function Dashboard() {
            <div className="relative z-10">
               <div className="inline-flex items-center gap-2 px-3 py-1 rounded-full bg-[var(--accent-glow)] border border-[var(--border-color)] text-[10px] font-black text-[var(--accent-primary)] uppercase tracking-widest mb-4">
                  <Sparkles className="w-3 h-3" />
-                 Podcastic Premium
+                 Podcastic
               </div>
               <h2 className="text-4xl lg:text-5xl font-display font-black mb-4 tracking-tight leading-tight max-w-2xl text-[var(--text-primary)]">
                  Découvrez les nouveautés de votre univers audio.

frontend/src/pages/Login.tsx

@@ -61,7 +61,7 @@ export default function Login() {
           <h1 className="text-5xl font-display font-black mb-3 tracking-tighter">PODCASTIC</h1>
           <div className="inline-flex items-center gap-2 px-3 py-1 rounded-full bg-[var(--bg-secondary)] border border-[var(--border-color)] text-[10px] font-black text-[var(--accent-primary)] uppercase tracking-[0.2em]">
              <Sparkles className="w-3 h-3" />
-             Expérience Audio Premium
+             Votre espace audio
           </div>
         </div>