Add i18n translations for page content (Home, Database, Logs)

Extended internationalization support by adding translation keys and data-i18n attributes to page content. Previously only the sidebar was translated - now the main content of Home, Database, and Logs pages will switch between French and English when the user changes the language selector.

Translation keys added:
- Home page: title, welcome message, PM measures, Linux stats, disk/memory usage
- Database page: all UI labels, buttons, and dropdown options
- Logs page: title, description, log types, and action buttons

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

html/lang/en.json

@@ -60,5 +60,42 @@
     "map": "Map",
     "terminal": "Terminal",
     "admin": "Admin"
+  },
+  "home": {
+    "title": "Your Sensor",
+    "welcome": "Welcome to your sensor configuration interface.",
+    "pmMeasures": "PM Measurements",
+    "linuxStats": "Linux Statistics",
+    "diskUsage": "Disk usage (total size",
+    "memoryUsage": "Memory usage (total size",
+    "databaseSize": "Database size:"
+  },
+  "database": {
+    "title": "Database",
+    "description": "The sensor records measurement data locally. You can view and download it here.",
+    "viewDatabase": "View Database",
+    "numberOfMeasures": "Number of measurements:",
+    "last10": "Last 10",
+    "last20": "Last 20",
+    "last30": "Last 30",
+    "pmMeasures": "PM Measurements",
+    "tempHumMeasures": "Temp/Hum Measurements",
+    "pm5Channels": "PM Measurements (5 channels)",
+    "cairsensProbe": "Cairsens Probe",
+    "noiseProbe": "Noise Probe",
+    "windProbe": "Wind Probe",
+    "battery": "Battery",
+    "timestampTable": "Timestamp Table",
+    "downloadData": "Download Data",
+    "startDate": "Start date:",
+    "endDate": "End date:"
+  },
+  "logs": {
+    "title": "The Log",
+    "description": "The log allows you to know if the sensor processes are running correctly.",
+    "saraLogs": "Sara logs",
+    "bootLogs": "Boot logs",
+    "refresh": "Refresh",
+    "clear": "Clear"
   }
 }