feat: bottom-aligned widgets and wind direction

- All environment widgets align content from bottom for visual harmony
- Wind chip now shows direction (e.g., "SE 14 km/h")

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

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

lib/shared/widgets/air_quality_widget.dart

@@ -69,14 +69,13 @@ class AirQualityWidget extends StatelessWidget {
             ),
             const SizedBox(height: 8),
 
-            // Content area with minimum height to match other widgets
-            ConstrainedBox(
-              constraints: const BoxConstraints(minHeight: 170),
+            // Content area with fixed height, content aligned to bottom
+            SizedBox(
+              height: 170,
               child: Column(
                 crossAxisAlignment: CrossAxisAlignment.start,
-                mainAxisSize: MainAxisSize.min,
+                mainAxisAlignment: MainAxisAlignment.end,
                 children: [
-                  const SizedBox(height: 8),
                   // AQI Display
                   Row(
                     children: [