feat(ui): add database stats card on database page

Show table info (entry count, oldest/newest dates, total DB size) in a
new card on the database page, with auto-refresh and i18n support.

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

html/database.html

@@ -108,7 +108,24 @@
             </div>
           </div>
 
-          <div class="col-lg-4 col-md-12 mb-3">
+          <div class="col-lg-4 col-md-6 mb-3">
+            <div class="card text-dark bg-light h-100">
+              <div class="card-body">
+                <h5 class="card-title" data-i18n="database.statsTitle">Informations sur la base</h5>
+                <div id="db_stats_content">
+                  <div class="text-center py-3">
+                    <div class="spinner-border spinner-border-sm" role="status"></div>
+                    <span class="ms-2" data-i18n="common.loading">Chargement...</span>
+                  </div>
+                </div>
+              </div>
+            </div>
+          </div>
+
+        </div>
+
+        <div class="row mb-3">
+          <div class="col-lg-4 col-md-6 mb-3">
             <div class="card text-white bg-danger h-100">
               <div class="card-body">
                 <h5 class="card-title" data-i18n="database.dangerZone">Zone dangereuse</h5>
@@ -118,7 +135,6 @@
               </div>
             </div>
           </div>
-
         </div>
 
         <div class="row mt-2">
@@ -224,6 +240,9 @@ window.onload = function() {
   }); //end ajax
 
 
+  // Get database table stats
+  loadDbStats();
+
   //get local RTC
   $.ajax({
       url: 'launcher.php?type=RTC_time',
@@ -478,6 +497,67 @@ function downloadCSV(response, table) {
     document.body.removeChild(a);
 }
 
+// Table display names
+const tableDisplayNames = {
+    'data_NPM': 'PM (NextPM)',
+    'data_NPM_5channels': 'PM 5 canaux',
+    'data_BME280': 'Temp/Hum (BME280)',
+    'data_envea': 'Gaz (Cairsens)',
+    'data_WIND': 'Vent',
+    'data_MPPT': 'Batterie (MPPT)',
+    'data_NOISE': 'Bruit'
+};
+
+function loadDbStats() {
+    $.ajax({
+        url: 'launcher.php?type=db_table_stats',
+        dataType: 'json',
+        method: 'GET',
+        success: function(response) {
+            if (!response.success) {
+                document.getElementById('db_stats_content').innerHTML =
+                    '<div class="alert alert-danger mb-0">' + (response.error || 'Erreur') + '</div>';
+                return;
+            }
+
+            let html = '<p class="mb-2"><strong data-i18n="database.statsDbSize">Taille totale:</strong> ' + response.size_mb + ' MB</p>';
+            html += '<div class="table-responsive"><table class="table table-sm table-bordered mb-0">';
+            html += '<thead class="table-secondary"><tr>';
+            html += '<th data-i18n="database.statsTable">Table</th>';
+            html += '<th data-i18n="database.statsCount">Entrées</th>';
+            html += '<th data-i18n="database.statsOldest">Plus ancienne</th>';
+            html += '<th data-i18n="database.statsNewest">Plus récente</th>';
+            html += '</tr></thead><tbody>';
+
+            response.tables.forEach(function(t) {
+                const displayName = tableDisplayNames[t.name] || t.name;
+                const oldest = t.oldest ? t.oldest.substring(0, 16) : '-';
+                const newest = t.newest ? t.newest.substring(0, 16) : '-';
+                html += '<tr>';
+                html += '<td>' + displayName + '</td>';
+                html += '<td>' + t.count.toLocaleString() + '</td>';
+                html += '<td><small>' + oldest + '</small></td>';
+                html += '<td><small>' + newest + '</small></td>';
+                html += '</tr>';
+            });
+
+            html += '</tbody></table></div>';
+            html += '<button class="btn btn-outline-secondary btn-sm mt-2" onclick="loadDbStats()" data-i18n="logs.refresh">Refresh</button>';
+
+            document.getElementById('db_stats_content').innerHTML = html;
+
+            // Re-apply translations if i18n is loaded
+            if (typeof i18n !== 'undefined' && i18n.translations && Object.keys(i18n.translations).length > 0) {
+                i18n.applyTranslations();
+            }
+        },
+        error: function(xhr, status, error) {
+            document.getElementById('db_stats_content').innerHTML =
+                '<div class="alert alert-danger mb-0">Erreur: ' + error + '</div>';
+        }
+    });
+}
+
 // Function to empty all sensor tables
 function emptySensorTables() {
     // Show confirmation dialog

html/lang/en.json

@@ -92,7 +92,13 @@
     "dangerZone": "Danger Zone",
     "dangerWarning": "Warning: This action is irreversible!",
     "emptyAllTables": "Empty all sensor tables",
-    "emptyTablesNote": "Note: Configuration and timestamp tables will be preserved."
+    "emptyTablesNote": "Note: Configuration and timestamp tables will be preserved.",
+    "statsTitle": "Database Information",
+    "statsDbSize": "Total size:",
+    "statsTable": "Table",
+    "statsCount": "Entries",
+    "statsOldest": "Oldest",
+    "statsNewest": "Newest"
   },
   "logs": {
     "title": "The Log",

html/lang/fr.json

@@ -92,7 +92,13 @@
     "dangerZone": "Zone dangereuse",
     "dangerWarning": "Attention: Cette action est irréversible!",
     "emptyAllTables": "Vider toutes les tables de capteurs",
-    "emptyTablesNote": "Note: Les tables de configuration et horodatage seront préservées."
+    "emptyTablesNote": "Note: Les tables de configuration et horodatage seront préservées.",
+    "statsTitle": "Informations sur la base",
+    "statsDbSize": "Taille totale:",
+    "statsTable": "Table",
+    "statsCount": "Entrées",
+    "statsOldest": "Plus ancienne",
+    "statsNewest": "Plus récente"
   },
   "logs": {
     "title": "Le journal",

html/launcher.php

@@ -530,6 +530,60 @@ if ($type == "database_size") {
     
 }
 
+if ($type == "db_table_stats") {
+    $databasePath = '/var/www/nebuleair_pro_4g/sqlite/sensors.db';
+
+    if (file_exists($databasePath)) {
+        try {
+            $db = new PDO("sqlite:$databasePath");
+
+            // Database file size
+            $fileSizeBytes = filesize($databasePath);
+            $fileSizeMB = round($fileSizeBytes / (1024 * 1024), 2);
+
+            // Sensor data tables to inspect
+            $tables = ['data_NPM', 'data_NPM_5channels', 'data_BME280', 'data_envea', 'data_WIND', 'data_MPPT', 'data_NOISE'];
+
+            $tableStats = [];
+            foreach ($tables as $tableName) {
+                // Check if table exists
+                $check = $db->query("SELECT name FROM sqlite_master WHERE type='table' AND name='$tableName'");
+                if ($check->fetch()) {
+                    $countResult = $db->query("SELECT COUNT(*) as cnt FROM $tableName")->fetch();
+                    $count = (int)$countResult['cnt'];
+
+                    $oldest = null;
+                    $newest = null;
+                    if ($count > 0) {
+                        $oldestResult = $db->query("SELECT MIN(timestamp) as ts FROM $tableName")->fetch();
+                        $newestResult = $db->query("SELECT MAX(timestamp) as ts FROM $tableName")->fetch();
+                        $oldest = $oldestResult['ts'];
+                        $newest = $newestResult['ts'];
+                    }
+
+                    $tableStats[] = [
+                        'name' => $tableName,
+                        'count' => $count,
+                        'oldest' => $oldest,
+                        'newest' => $newest
+                    ];
+                }
+            }
+
+            echo json_encode([
+                'success' => true,
+                'size_mb' => $fileSizeMB,
+                'size_bytes' => $fileSizeBytes,
+                'tables' => $tableStats
+            ]);
+        } catch (PDOException $e) {
+            echo json_encode(['success' => false, 'error' => 'Database query failed: ' . $e->getMessage()]);
+        }
+    } else {
+        echo json_encode(['success' => false, 'error' => 'Database file not found']);
+    }
+}
+
 if ($type == "linux_disk") {
     $command = 'df -h /';
     $output = shell_exec($command);