Add task list page for Video Learning sessions

This commit adds a dedicated task list page to view and manage all video
learning sessions, solving the issue where users couldn't find their
background tasks after navigating away.

Features:
- New sessions.html page with card-based layout for all sessions
- Real-time polling for session status updates (every 3 seconds)
- Session control buttons (pause/resume/stop/delete)
- localStorage integration for session persistence across page refreshes
- Navigation links added to main page and video learning page
- Empty state UI when no sessions exist

New files:
- dashboard/static/sessions.html - Task list page
- dashboard/static/js/sessions.js - Sessions module with API calls
- dashboard/static/css/sessions.css - Styling for sessions page

Modified files:
- dashboard/api/video_learning.py - Added /sessions/list endpoint
- dashboard/static/index.html - Added "任务列表" button
- dashboard/static/video-learning.html - Added "任务列表" button and localStorage

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

dashboard/static/js/sessions.js

@@ -0,0 +1,120 @@
+/**
+ * Video Learning Sessions Module for AutoGLM Dashboard
+ *
+ * This module provides functionality for managing video learning sessions,
+ * including listing, controlling, and monitoring sessions.
+ */
+
+const SessionsModule = {
+    // Current session state
+    sessions: [],
+    isLoading: false,
+
+    /**
+     * Load all sessions
+     */
+    async loadSessions() {
+        try {
+            const response = await axios.get('/api/video-learning/sessions/list');
+            this.sessions = response.data;
+            return this.sessions;
+        } catch (error) {
+            console.error('Error loading sessions:', error);
+            throw error;
+        }
+    },
+
+    /**
+     * Get session status
+     */
+    async getSessionStatus(sessionId) {
+        try {
+            const response = await axios.get(`/api/video-learning/sessions/${sessionId}/status`);
+            return response.data;
+        } catch (error) {
+            console.error('Error getting session status:', error);
+            throw error;
+        }
+    },
+
+    /**
+     * Get session videos
+     */
+    async getSessionVideos(sessionId) {
+        try {
+            const response = await axios.get(`/api/video-learning/sessions/${sessionId}/videos`);
+            return response.data;
+        } catch (error) {
+            console.error('Error getting session videos:', error);
+            throw error;
+        }
+    },
+
+    /**
+     * Control session (pause/resume/stop)
+     */
+    async controlSession(sessionId, action) {
+        try {
+            const response = await axios.post(`/api/video-learning/sessions/${sessionId}/control`, {
+                action: action
+            });
+            return response.data;
+        } catch (error) {
+            console.error('Error controlling session:', error);
+            throw error;
+        }
+    },
+
+    /**
+     * Delete session
+     */
+    async deleteSession(sessionId) {
+        try {
+            const response = await axios.delete(`/api/video-learning/sessions/${sessionId}`);
+            return response.data;
+        } catch (error) {
+            console.error('Error deleting session:', error);
+            throw error;
+        }
+    },
+
+    /**
+     * Format platform name
+     */
+    getPlatformName(platform) {
+        const names = {
+            'douyin': '抖音',
+            'kuaishou': '快手',
+            'tiktok': 'TikTok'
+        };
+        return names[platform] || platform;
+    },
+
+    /**
+     * Get status text
+     */
+    getStatusText(session) {
+        if (!session.is_active && !session.is_paused) return '已完成';
+        if (session.is_paused) return '已暂停';
+        if (session.is_active) return '进行中';
+        return '未知';
+    },
+
+    /**
+     * Format duration
+     */
+    formatDuration(seconds) {
+        if (!seconds) return '0s';
+        if (seconds < 60) {
+            return `${seconds.toFixed(1)}s`;
+        }
+        const minutes = Math.floor(seconds / 60);
+        const remainingSeconds = seconds % 60;
+        return `${minutes}m ${remainingSeconds.toFixed(1)}s`;
+    }
+};
+
+// Export for use in other modules
+if (typeof module !== 'undefined' && module.exports) {
+    module.exports = SessionsModule;
+}