feat: intégration TMDB — poster, backdrop, lien fiche

- tmdb.py : recherche TMDB par title+subtitle, matching fuzzy,
  cache SQLite 30 jours (table tmdb_cache dans arte_dl.db)
- arte_api.py : enrichissement concurrent (5 workers) après résolution
  des IDs ; ajoute tmdb_id, tmdb_poster, tmdb_backdrop au concert
- app.js : backdrop TMDB utilisé comme thumbnail de carte quand dispo ;
  subtitle affiché sous le titre de carte ; poster dans la modal ;
  lien direct vers la fiche TMDB
- docker-compose.yml : passage de TMDB_API_KEY au container

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

static/app.js

@@ -102,12 +102,14 @@ function renderConcerts(data) {
   statusText.textContent = `${total} concert${total > 1 ? 's' : ''} · page ${state.page} / ${pages}`;
 
   grid.innerHTML = concerts.map(c => {
-    const thumb = c.thumbnail
-      ? `<img class="card-thumb" src="${c.thumbnail}" alt="" loading="lazy" />`
+    const imgSrc = c.tmdb_backdrop || c.thumbnail;
+    const thumb = imgSrc
+      ? `<img class="card-thumb" src="${imgSrc}" alt="" loading="lazy" />`
       : `<div class="card-thumb" style="background:#1a1a1a"></div>`;
     const dur = c.duration ? `<span class="card-duration">${fmtDuration(c.duration)}</span>` : '';
     const dl  = state.downloadedUrls.has(c.url) ? `<span class="card-downloaded">✓ Téléchargé</span>` : '';
     const date = fmtDate(c.upload_date);
+    const sub  = c.subtitle ? `<div class="card-subtitle">${c.subtitle}</div>` : '';
 
     return `
       <div class="card" data-id="${c.id}" tabindex="0" role="button" aria-label="${c.title}">
@@ -116,6 +118,7 @@ function renderConcerts(data) {
         </div>
         <div class="card-info">
           <div class="card-title">${c.title}</div>
+          ${sub}
           ${date ? `<div class="card-date">${date}</div>` : ''}
         </div>
       </div>`;
@@ -175,9 +178,20 @@ pagination.addEventListener('click', e => {
 function openModal(concert) {
   state.current = concert;
 
-  $('modal-thumb').src  = concert.thumbnail || '';
+  const modalThumbEl = $('modal-thumb');
+  modalThumbEl.src = concert.tmdb_backdrop || concert.thumbnail || '';
+
+  const posterEl = $('modal-poster');
+  if (concert.tmdb_poster) {
+    posterEl.src = concert.tmdb_poster;
+    posterEl.hidden = false;
+  } else {
+    posterEl.hidden = true;
+  }
+
   $('modal-title').textContent = concert.title;
   $('modal-meta').textContent = [
+    concert.subtitle || '',
     concert.duration ? fmtDuration(concert.duration) : '',
     concert.upload_date ? fmtDate(concert.upload_date) : '',
   ].filter(Boolean).join('  ·  ');
@@ -185,6 +199,14 @@ function openModal(concert) {
   $('modal-dur-badge').textContent = concert.duration ? fmtDuration(concert.duration) : '';
   $('btn-watch').href = concert.url || '#';
 
+  const btnTmdb = $('btn-tmdb');
+  if (concert.tmdb_id) {
+    btnTmdb.href = `https://www.themoviedb.org/movie/${concert.tmdb_id}`;
+    btnTmdb.hidden = false;
+  } else {
+    btnTmdb.hidden = true;
+  }
+
   const btnDl = $('btn-download');
   const alreadyDone = state.downloadedUrls.has(concert.url);
   btnDl.textContent = alreadyDone ? '✓ Déjà téléchargé' : 'Télécharger';

static/style.css

@@ -337,6 +337,16 @@ body {
   overflow: hidden;
 }
 
+.card-subtitle {
+  margin-top: 3px;
+  font-size: 11.5px;
+  color: var(--gold);
+  letter-spacing: 0.02em;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
 .card-date {
   margin-top: 6px;
   font-size: 11.5px;
@@ -483,6 +493,26 @@ body {
   background: linear-gradient(to bottom, transparent 50%, var(--surface) 100%);
 }
 
+.modal-head {
+  display: flex;
+  align-items: flex-start;
+  gap: 14px;
+  margin-bottom: 14px;
+}
+
+.modal-head-text { flex: 1; min-width: 0; }
+
+.modal-poster {
+  width: 64px;
+  flex-shrink: 0;
+  border-radius: 6px;
+  box-shadow: 0 4px 16px rgba(0,0,0,0.5);
+  object-fit: cover;
+  margin-top: 2px;
+}
+
+.modal-poster[hidden] { display: none; }
+
 .modal-duration-badge {
   position: absolute;
   bottom: 12px; right: 12px;
@@ -505,14 +535,13 @@ body {
   font-size: 22px;
   font-weight: 700;
   line-height: 1.3;
-  margin-bottom: 8px;
+  margin-bottom: 6px;
 }
 
 .modal-meta {
   font-size: 12.5px;
   color: var(--gold);
   letter-spacing: 0.04em;
-  margin-bottom: 14px;
 }
 
 .modal-desc {