feat(board): étiquettes gérables, notes repliable/redimensionnable/auto-save

- modale Étiquettes: liste, création (nom + couleur + palette),
  suppression via DELETE (CSRF par en-tête); panneau détail:
  bascules d'étiquettes par issue avec mise à jour immédiate des
  chips de la carte; _issue_payload expose les ids d'étiquettes
- API étiquettes dans main (routes repos + toggle issue)
- notes: bouton replier/déplier et largeur par glisser, persistés
  par projet (localStorage), sauvegarde automatique débouncée
  avec statut, formulaire repris par board.js (HTMX retiré du board)
- nouvelles pages search/my/briefing; navigation enrichie partout
  (Mes issues, Briefing, Recherche); CSS associé

static/css/style.css

@@ -719,6 +719,154 @@ footer {
 .activity-text { flex: 1; }
 .card-date { color: var(--text-3); }
 
+/* ── Search / my issues / briefing ──────────── */
+.search-hero { display: flex; gap: 10px; margin-bottom: 18px; }
+.search-hero input {
+    flex: 1;
+    padding: 13px 18px;
+    border-radius: 999px;
+    border: 1px solid var(--border);
+    background: var(--surface);
+    color: var(--text);
+    font-size: 1rem;
+    outline: none;
+}
+.search-hero input:focus { border-color: var(--accent); box-shadow: var(--ring); }
+.issue-results { display: flex; flex-direction: column; gap: 7px; }
+.issue-row {
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    flex-wrap: wrap;
+    background: linear-gradient(180deg, var(--surface-2), var(--surface));
+    border: 1px solid var(--border);
+    border-radius: var(--radius-sm);
+    padding: 10px 14px;
+    font-size: 0.9rem;
+    transition: border-color 0.15s;
+}
+.issue-row:hover { border-color: var(--border-strong); }
+.issue-main { color: var(--text); flex: 1; min-width: 220px; }
+.issue-main:hover { color: #a5c4fd; text-decoration: none; }
+.col-chip {
+    padding: 2px 10px;
+    border-radius: 999px;
+    font-size: 0.72rem;
+    font-weight: 700;
+}
+.briefing-tiles { margin-bottom: 18px; }
+.briefing-card {
+    background: linear-gradient(180deg, var(--surface-2), var(--surface));
+    border: 1px solid var(--border);
+    border-radius: var(--radius);
+    padding: 20px;
+    margin-bottom: 16px;
+}
+.briefing-card h2 { font-size: 1.02rem; margin-bottom: 12px; }
+.briefing-text {
+    white-space: pre-wrap;
+    font-family: inherit;
+    font-size: 0.9rem;
+    line-height: 1.6;
+    color: var(--text);
+}
+.briefing-card code, .empty-state code {
+    background: var(--surface-3);
+    padding: 1px 6px;
+    border-radius: 5px;
+    font-size: 0.82em;
+}
+
+/* ── Notes panel v2 ─────────────────────────── */
+.notes-panel { position: relative; transition: width 0.18s ease; }
+.notes-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 6px; }
+.notes-head h3 { margin-bottom: 0; }
+.notes-toggle { padding: 4px 10px; }
+.notes-panel.collapsed { width: 54px !important; padding: 14px 10px; }
+.notes-panel.collapsed .notes-body-wrap { display: none; }
+.notes-panel.collapsed .notes-head h3 { display: none; }
+.notes-panel.collapsed .notes-head { justify-content: center; }
+.notes-resize {
+    position: absolute;
+    left: -3px; top: 0;
+    width: 7px; height: 100%;
+    cursor: col-resize;
+    z-index: 5;
+}
+.notes-resize:hover { background: rgba(124, 92, 252, 0.35); }
+.notes-foot { display: flex; justify-content: space-between; align-items: center; gap: 10px; margin-top: 10px; }
+.notes-foot .btn-save { margin-top: 0; }
+.notes-status { font-size: 0.76rem; color: var(--text-3); }
+
+/* ── Label manager + toggles ────────────────── */
+.modal {
+    position: fixed; inset: 0;
+    background: rgba(4, 6, 10, 0.6);
+    backdrop-filter: blur(3px);
+    z-index: 300;
+    display: flex;
+    align-items: flex-start;
+    justify-content: center;
+    padding: 8vh 16px 16px;
+}
+.modal[hidden] { display: none; }
+.modal-box {
+    background: var(--surface);
+    border: 1px solid var(--border-strong);
+    border-radius: var(--radius);
+    box-shadow: var(--shadow);
+    width: min(560px, 94vw);
+    max-height: 80vh;
+    overflow-y: auto;
+    padding: 22px;
+    animation: drawer-in 0.22s cubic-bezier(0.2, 0.8, 0.3, 1);
+}
+.modal-box h2 { font-size: 1.1rem; }
+.label-list { display: flex; flex-direction: column; gap: 8px; margin: 14px 0; }
+.label-row {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    background: var(--surface-2);
+    border: 1px solid var(--border);
+    border-radius: var(--radius-sm);
+    padding: 8px 12px;
+}
+.label-del { font-size: 0.78rem; padding: 5px 10px; }
+.label-create-form { display: flex; gap: 8px; align-items: center; }
+.label-create-form input[type="text"] {
+    flex: 1;
+    padding: 10px 14px;
+    border-radius: var(--radius-sm);
+    border: 1px solid var(--border);
+    background: var(--bg);
+    color: var(--text);
+    outline: none;
+}
+.label-create-form input[type="text"]:focus { border-color: var(--accent); box-shadow: var(--ring); }
+.label-create-form input[type="color"] {
+    width: 44px; height: 40px;
+    border: 1px solid var(--border);
+    border-radius: var(--radius-sm);
+    background: var(--bg);
+    cursor: pointer;
+    padding: 3px;
+}
+.label-swatches { display: flex; gap: 6px; margin-top: 10px; }
+.swatch {
+    width: 22px; height: 22px;
+    border-radius: 50%;
+    border: 2px solid rgba(255,255,255,0.25);
+    cursor: pointer;
+    padding: 0;
+}
+.swatch:hover { transform: scale(1.15); }
+.detail-labels-manage { margin: 4px 0 10px; }
+.label-toggles { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 6px; }
+.label-toggle { cursor: pointer; opacity: 0.45; transition: opacity 0.15s, transform 0.1s; }
+.label-toggle:hover { opacity: 0.85; }
+.label-toggle.on { opacity: 1; box-shadow: 0 0 0 1.5px currentColor inset; }
+
 /* ── Responsive ─────────────────────────────── */
 @media (max-width: 900px) {
     .hero { flex-direction: column; align-items: flex-start; }