feat: sync DB prefs, update history tab, configurable dashboard shortcuts

- auth store fetchMe(): sync theme/sidebar_position/lang from DB to localStorage+stores on login/refresh
- profilePage setters: PATCH /api/auth/preferences on every preference change
- updatesPage: add history tab (GET /api/updates/history) with job list, click to view output
- dashboardPage: load shortcuts from settings API, fall back to defaults if none configured
- settingsPage: new Raccourcis tab to add/remove/configure dashboard shortcuts (saved as JSON)
- settings.go: expose dashboard_shortcuts in publicSettings for GET/PUT access
- pages.css: add .history-table, .shortcut-row styles

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

frontend/updates.html

@@ -55,6 +55,17 @@
   <main id="swup" class="page-content transition-fade">
     <div x-data="updatesPage()" x-cloak>
 
+      <!-- Tabs -->
+      <div class="tabs">
+        <button class="tab-btn" :class="{ active: activeTab === 'targets' }" @click="activeTab = 'targets'">Cibles</button>
+        <button class="tab-btn" :class="{ active: activeTab === 'history' }" @click="activeTab = 'history'; loadHistory()">
+          <i class="lnid-clock-1"></i> Historique
+        </button>
+      </div>
+
+      <!-- Tab: Cibles -->
+      <div x-show="activeTab === 'targets'">
+
       <!-- Actions globales -->
       <div class="page-actions">
         <div class="page-actions-left">
@@ -150,6 +161,38 @@
         </div>
         <pre class="output-content" x-text="output" x-ref="output"></pre>
       </div>
+
+      </div><!-- /tab targets -->
+
+      <!-- Tab: Historique -->
+      <div x-show="activeTab === 'history'">
+        <div class="loading-state" x-show="historyLoading">
+          <div class="spinner-lg"></div>
+          <span>Chargement…</span>
+        </div>
+        <div x-show="!historyLoading">
+          <p class="empty-state" x-show="history.length === 0">Aucune mise à jour effectuée</p>
+          <div class="history-table" x-show="history.length > 0">
+            <div class="history-header">
+              <span>Job</span>
+              <span>Cible</span>
+              <span>Statut</span>
+              <span>Date</span>
+              <span>Durée</span>
+            </div>
+            <template x-for="h in history" :key="h.job_id">
+              <div class="history-row" @click="output = h.output; currentJob = h.job_id; jobStatus = h.status; activeTab = 'targets'">
+                <span class="history-job" x-text="h.job_id.slice(0,8)"></span>
+                <span class="history-target" x-text="h.target"></span>
+                <span class="history-status badge" :class="h.status" x-text="h.status"></span>
+                <span class="history-date" x-text="formatDate(h.started_at)"></span>
+                <span class="history-dur" x-text="h.finished_at ? '' : '—'"></span>
+              </div>
+            </template>
+          </div>
+        </div>
+      </div><!-- /tab history -->
+
     </div>
   </main>
 </div>