v2.4.0

Air Quality Card v2.4.0

New: Outdoor Sensor Comparison (closes #5)

Thanks to @BradleyFord for the excellent feature request!

• Optional outdoor sensor entities for all 6 sensor types (CO2, PM2.5, HCHO, tVOC, humidity, temperature)
• Dashed comparison line overlaid on each graph when outdoor data is configured
• Dual tooltips — hover any graph to see both indoor and outdoor values
• Current outdoor values shown next to indoor readings (e.g., 851 ppm Excellent (out: 420 ppm))
• Smart recommendations — the card won't suggest opening windows when outdoor air is worse than indoor:
  • "Keep Windows Closed" replaces "Open Window" / "Ventilate Now" when outdoor PM2.5 or CO2 exceeds indoor levels
  • Contextual subtitles like "Outdoor PM2.5 at 85 µg/m³ - poor outdoor air"
  • "Run Air Purifier" still recommended when indoor PM2.5 is high regardless of outdoor conditions

No Breaking Changes

• All outdoor entities are optional — card behaves identically to v2.3.0 when none are configured
• Existing configurations require zero changes
• Visual editor includes a new collapsible "Outdoor Sensors" section