Add complete frontend interface with Jinja2 templates

- Created base.html template with navigation and flash messages
- Created dashboard.html for video listing sorted by date
- Created channels.html for channel management
- Created add_channel.html with subscription form
- Created watch.html with HTML5 video player
- Created static/style.css with YouTube-inspired dark theme
- Updated main.py with frontend routes:
  - / (index): Dashboard with all videos
  - /channels: Channel management page
  - /add-channel: Add new channel form (GET/POST)
  - /watch/<video_id>: Video player page
- Added new API endpoints:
  - /api/videos/refresh/<channel_id>: Refresh channel videos
  - /api/video/stream/<video_id>: Stream/download video files
- Enhanced /api/download/<video_id> with status checks
- Updated CLAUDE.md with comprehensive frontend documentation

Features:
- Video grid with thumbnails and download status badges
- Inline download buttons for pending videos
- Channel subscription and refresh functionality
- HTML5 video player for downloaded videos
- Auto-refresh during video downloads
- Responsive design for mobile/desktop
- Flash message system for user feedback
- Dark theme with hover effects and animations

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

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

templates/channels.html

@@ -0,0 +1,75 @@
+{% extends "base.html" %}
+
+{% block title %}Channels - YottoB{% endblock %}
+
+{% block content %}
+<div class="channels-page">
+    <div class="page-header">
+        <h2>Subscribed Channels</h2>
+        <a href="/add-channel" class="btn btn-primary">Add New Channel</a>
+    </div>
+
+    {% if channels %}
+        <div class="channels-list">
+            {% for channel in channels %}
+                <div class="channel-card">
+                    <div class="channel-info">
+                        <h3 class="channel-title">{{ channel.title }}</h3>
+                        <p class="channel-url">
+                            <a href="{{ channel.rss_url }}" target="_blank">{{ channel.rss_url }}</a>
+                        </p>
+                        <div class="channel-meta">
+                            <span class="video-count">{{ channel.video_entries|length }} videos</span>
+                            <span class="last-updated">
+                                Last updated: {{ channel.last_fetched_at.strftime('%b %d, %Y %I:%M %p') if channel.last_fetched_at else 'Never' }}
+                            </span>
+                        </div>
+                    </div>
+                    <div class="channel-actions">
+                        <button class="btn btn-secondary" onclick="refreshChannel({{ channel.id }})">
+                            Refresh Videos
+                        </button>
+                        <a href="/?channel={{ channel.id }}" class="btn btn-link">View Videos</a>
+                    </div>
+                </div>
+            {% endfor %}
+        </div>
+    {% else %}
+        <div class="empty-state">
+            <h3>No channels subscribed</h3>
+            <p>Add your first YouTube channel to start downloading videos</p>
+            <a href="/add-channel" class="btn btn-primary">Add Channel</a>
+        </div>
+    {% endif %}
+</div>
+{% endblock %}
+
+{% block scripts %}
+<script>
+    function refreshChannel(channelId) {
+        const button = event.target;
+        button.disabled = true;
+        button.textContent = 'Refreshing...';
+
+        fetch(`/api/videos/refresh/${channelId}`, {
+            method: 'POST'
+        })
+        .then(response => response.json())
+        .then(data => {
+            if (data.status === 'success') {
+                alert(`Refreshed! Found ${data.new_videos} new videos`);
+                location.reload();
+            } else {
+                alert('Failed to refresh: ' + data.message);
+                button.disabled = false;
+                button.textContent = 'Refresh Videos';
+            }
+        })
+        .catch(error => {
+            alert('Error: ' + error);
+            button.disabled = false;
+            button.textContent = 'Refresh Videos';
+        });
+    }
+</script>
+{% endblock %}