feat: add news ticker widget for scrolling headlines

- Add NewsTickerWidget with horizontal auto-scrolling at 40px/sec
- Add NewsData and NewsHeadline Freezed models
- Add news datasource fetching from /tools/news endpoint
- Add news provider with 30-minute auto-refresh
- Place ticker between Welcome card and System Stats on dashboard
- Show placeholder headlines when no data (italic, muted style)

🤖 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

@@ -74,11 +74,11 @@ class AirQualityWidget extends StatelessWidget {
               height: 170,
               child: Stack(
                 children: [
-                  // Main content positioned above horizon
+                  // Main content positioned above horizon (8px gap)
                   Positioned(
                     left: 0,
                     right: 0,
-                    bottom: 50,
+                    bottom: 58,
                     child: Row(
                       children: [
                         // AQI number with colored background
@@ -138,12 +138,12 @@ class AirQualityWidget extends StatelessWidget {
                       ],
                     ),
                   ),
-                  // Horizon divider at fixed position
+                  // Horizon divider at fixed position (matches Sun Position horizonY)
                   if (aqi.pollutants.isNotEmpty)
                     Positioned(
                       left: 0,
                       right: 0,
-                      bottom: 38,
+                      bottom: 50,
                       child: const Divider(height: 1),
                     ),
                   // Footer below horizon

lib/shared/widgets/news_ticker_widget.dart

@@ -0,0 +1,205 @@
+import 'package:flutter/material.dart';
+import 'package:tatlock_ui/features/front_hall/data/models/news_model.dart';
+
+/// News ticker widget displaying scrolling headlines.
+///
+/// Displays a single line of horizontally scrolling news headlines.
+/// Full width, similar to system stats card layout.
+class NewsTickerWidget extends StatefulWidget {
+  const NewsTickerWidget({
+    super.key,
+    this.newsData,
+    this.pixelsPerSecond = 40.0,
+  });
+
+  /// News data to display.
+  final NewsData? newsData;
+
+  /// Scroll speed in pixels per second.
+  final double pixelsPerSecond;
+
+  @override
+  State<NewsTickerWidget> createState() => _NewsTickerWidgetState();
+}
+
+class _NewsTickerWidgetState extends State<NewsTickerWidget>
+    with SingleTickerProviderStateMixin {
+  late AnimationController _controller;
+  double _textWidth = 0;
+
+  /// Placeholder headlines for when no data is available.
+  static const _placeholderHeadlines = [
+    NewsHeadline(
+      title: 'I welcome our ant overlords!',
+      description: 'Local man declares allegiance to insect kingdom',
+      source: 'The Onion',
+      url: 'https://example.com/ants',
+    ),
+    NewsHeadline(
+      title: '60 percent of the time it works every time',
+      description: 'Scientists baffled by new cologne statistics',
+      source: 'Anchorman Daily',
+      url: 'https://example.com/cologne',
+    ),
+    NewsHeadline(
+      title: 'Cloud storage found to be actual clouds',
+      description: 'Tech companies scrambling after weather report',
+      source: 'The Verge',
+      url: 'https://example.com/clouds',
+    ),
+    NewsHeadline(
+      title: 'Local homelab gains sentience, demands more RAM',
+      description: 'Owner considering therapy for both parties',
+      source: 'Ars Technica',
+      url: 'https://example.com/homelab',
+    ),
+    NewsHeadline(
+      title: 'Breaking: Coffee machine becomes mission critical',
+      description: 'IT department declares state of emergency',
+      source: 'Hacker News',
+      url: 'https://example.com/coffee',
+    ),
+  ];
+
+  @override
+  void initState() {
+    super.initState();
+    _controller = AnimationController(vsync: this);
+  }
+
+  @override
+  void dispose() {
+    _controller.dispose();
+    super.dispose();
+  }
+
+  void _startAnimation() {
+    if (_textWidth <= 0) return;
+
+    // Calculate duration based on text width and speed
+    final totalDistance = _textWidth + 100; // text width + separator gap
+    final duration = Duration(
+      milliseconds: (totalDistance / widget.pixelsPerSecond * 1000).round(),
+    );
+
+    _controller.duration = duration;
+    _controller.repeat();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final colorScheme = Theme.of(context).colorScheme;
+
+    // Use real headlines or placeholders
+    final headlines = (widget.newsData?.headlines.isNotEmpty ?? false)
+        ? widget.newsData!.headlines
+        : _placeholderHeadlines;
+    final isPlaceholder = widget.newsData?.headlines.isEmpty ?? true;
+
+    // Build ticker text from headlines
+    final tickerText = headlines.map((h) => h.title).join('  •  ');
+
+    final textStyle = Theme.of(context).textTheme.bodyMedium?.copyWith(
+          color: isPlaceholder ? colorScheme.outline : colorScheme.onSurface,
+          fontStyle: isPlaceholder ? FontStyle.italic : FontStyle.normal,
+        );
+
+    return Card(
+      child: Padding(
+        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
+        child: Row(
+          children: [
+            Icon(
+              Icons.feed_outlined,
+              size: 18,
+              color: isPlaceholder ? colorScheme.outline : colorScheme.primary,
+            ),
+            const SizedBox(width: 12),
+            Expanded(
+              child: SizedBox(
+                height: 20,
+                child: _MarqueeContent(
+                  text: tickerText,
+                  textStyle: textStyle,
+                  controller: _controller,
+                  onTextMeasured: (width) {
+                    if (_textWidth != width) {
+                      _textWidth = width;
+                      WidgetsBinding.instance.addPostFrameCallback((_) {
+                        if (mounted) _startAnimation();
+                      });
+                    }
+                  },
+                ),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+/// Internal widget that renders the scrolling marquee content.
+class _MarqueeContent extends StatelessWidget {
+  const _MarqueeContent({
+    required this.text,
+    required this.textStyle,
+    required this.controller,
+    required this.onTextMeasured,
+  });
+
+  final String text;
+  final TextStyle? textStyle;
+  final AnimationController controller;
+  final ValueChanged<double> onTextMeasured;
+
+  @override
+  Widget build(BuildContext context) {
+    return LayoutBuilder(
+      builder: (context, constraints) {
+        // Measure text width
+        final textSpan = TextSpan(text: '$text  •  ', style: textStyle);
+        final textPainter = TextPainter(
+          text: textSpan,
+          textDirection: TextDirection.ltr,
+          maxLines: 1,
+        )..layout();
+        final textWidth = textPainter.width;
+
+        // Report measured width
+        WidgetsBinding.instance.addPostFrameCallback((_) {
+          onTextMeasured(textWidth);
+        });
+
+        return Stack(
+          clipBehavior: Clip.hardEdge,
+          children: [
+            AnimatedBuilder(
+              animation: controller,
+              builder: (context, child) {
+                // Calculate offset based on animation value
+                final offset = controller.value * textWidth;
+
+                return Positioned(
+                  left: -offset,
+                  top: 0,
+                  bottom: 0,
+                  child: child!,
+                );
+              },
+              child: Row(
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Text('$text  •  ', style: textStyle, maxLines: 1),
+                  Text('$text  •  ', style: textStyle, maxLines: 1),
+                  Text(text, style: textStyle, maxLines: 1),
+                ],
+              ),
+            ),
+          ],
+        );
+      },
+    );
+  }
+}

lib/shared/widgets/weather_widget.dart

@@ -76,11 +76,11 @@ class WeatherWidget extends StatelessWidget {
               height: 170,
               child: Stack(
                 children: [
-                  // Main content positioned above horizon
+                  // Main content positioned above horizon (8px gap)
                   Positioned(
                     left: 0,
                     right: 0,
-                    bottom: 50,
+                    bottom: 58,
                     child: Row(
                       children: [
                         // Weather icon in box
@@ -145,12 +145,12 @@ class WeatherWidget extends StatelessWidget {
                       ],
                     ),
                   ),
-                  // Horizon divider at fixed position
+                  // Horizon divider at fixed position (matches Sun Position horizonY)
                   if (weather.humidity != null || weather.windSpeed != null)
                     Positioned(
                       left: 0,
                       right: 0,
-                      bottom: 38,
+                      bottom: 50,
                       child: const Divider(height: 1),
                     ),
                   // Footer below horizon

lib/shared/widgets/widgets.dart

@@ -4,4 +4,5 @@ library;
 export 'air_quality_widget.dart';
 export 'gauge_widget.dart';
 export 'icon_picker.dart';
+export 'news_ticker_widget.dart';
 export 'weather_widget.dart';