feat: 学员详情页改为学习历程时间线，显示目标启动/达成和方案生成记录

app/templates/student.html

@@ -46,7 +46,7 @@
     <div class="col-md-8">
         <div class="card mb-4">
             <div class="card-header d-flex justify-content-between align-items-center">
-                <h6 class="mb-0"><i class="bi bi-list-check"></i> 问题记录</h6>
+                <h6 class="mb-0"><i class="bi bi-list-check"></i> 当前问题</h6>
                 <button class="btn btn-sm btn-primary" onclick="showAddProblemModal()">
                     <i class="bi bi-plus"></i> 添加问题
                 </button>
@@ -474,23 +474,112 @@ function renderProblemList(problems) {
     `).join('');
 }
 
+// 学习历程时间线（替代原 loadPlans）
 async function loadPlans() {
-    try {
-        const resp = await fetch(`/api/students/${currentStudentId}/plans`);
-        const plans = await resp.json();
-        renderPlanList(plans);
-    } catch (e) {
-        document.getElementById('planList').innerHTML = '<p class="text-danger">加载失败</p>';
-    }
+    await loadTimeline();
 }
 
-function renderPlanList(plans) {
+// 学习历程时间线
+async function loadTimeline() {
+    const [plansRes, goalsRes] = await Promise.all([
+        fetch(`/api/students/${currentStudentId}/plans`),
+        fetch(`/api/students/${currentStudentId}/goals`)
+    ]);
+    const plans = await plansRes.json();
+    const goals = await goalsRes.json();
+
+    // 构建时间线条目
+    const timeline = [];
+
+    // 添加目标开始记录
+    goals.forEach(g => {
+        if (g.start_date) {
+            const startDate = new Date(g.start_date);
+            const endDate = g.assessment_date ? new Date(g.assessment_date) : null;
+            const days = endDate ? Math.ceil((endDate - startDate) / (1000*60*60*24)) : null;
+            timeline.push({
+                date: startDate,
+                type: 'goal_start',
+                goal: g,
+                days: days,
+                endDate: endDate
+            });
+        }
+        // 添加目标达成记录
+        if (g.achievement_date) {
+            timeline.push({
+                date: new Date(g.achievement_date),
+                type: 'goal_achieved',
+                goal: g
+            });
+        }
+    });
+
+    // 添加方案生成记录
+    plans.forEach(p => {
+        timeline.push({
+            date: new Date(p.created_at),
+            type: 'plan',
+            plan: p
+        });
+    });
+
+    // 按时间逆序排序
+    timeline.sort((a, b) => b.date - a.date);
+
+    renderTimeline(timeline);
+}
+
+function renderTimeline(timeline) {
     const container = document.getElementById('planList');
-    if (plans.length === 0) {
-        container.innerHTML = '<p class="text-muted">暂无练习方案</p>';
+    if (timeline.length === 0) {
+        container.innerHTML = '<p class="text-muted">暂无学习记录</p>';
         return;
     }
-    container.innerHTML = plans.map(p => `
+
+    container.innerHTML = timeline.map(entry => {
+        if (entry.type === 'goal_start') {
+            const g = entry.goal;
+            return `
+            <div class="d-flex align-items-start mb-2 p-2 border rounded border-primary">
+                <div class="me-2">
+                    <span class="badge bg-primary">目标启动</span>
+                </div>
+                <div class="flex-grow-1">
+                    <div class="d-flex justify-content-between align-items-start">
+                        <div>
+                            <strong>${escapeHtml(g.goal_name)}</strong>
+                            <span class="text-muted ms-2">${formatDate(entry.date)}</span>
+                        </div>
+                        <span class="badge bg-secondary">预期 ${entry.days} 天</span>
+                    </div>
+                    <div class="small text-muted">
+                        ${g.goal_level || '入门'} | ${g.goal_category || '综合'} | 评估日期: ${entry.endDate ? formatDate(entry.endDate) : '未设置'}
+                    </div>
+                </div>
+            </div>`;
+        } else if (entry.type === 'goal_achieved') {
+            const g = entry.goal;
+            const stars = '⭐'.repeat(g.mastery_level || 1);
+            return `
+            <div class="d-flex align-items-start mb-2 p-2 border rounded border-success">
+                <div class="me-2">
+                    <span class="badge bg-success">目标达成</span>
+                </div>
+                <div class="flex-grow-1">
+                    <div class="d-flex justify-content-between align-items-start">
+                        <div>
+                            <strong>${escapeHtml(g.goal_name)}</strong>
+                            <span class="text-muted ms-2">${formatDate(entry.date)}</span>
+                        </div>
+                        <span>${stars}</span>
+                    </div>
+                    ${g.comment ? `<div class="small text-muted mt-1"><em>"${escapeHtml(g.comment)}"</em></div>` : ''}
+                </div>
+            </div>`;
+        } else {
+            const p = entry.plan;
+            return `
             <div class="d-flex align-items-start mb-2 p-2 border rounded ${p.is_typical ? 'border-warning bg-light' : ''}">
                 <div class="form-check me-2">
                     <input class="form-check-input" type="checkbox" id="typical-${p.id}" ${p.is_typical ? 'checked' : ''} onchange="toggleTypical(${p.id})">
@@ -499,7 +588,7 @@ function renderPlanList(plans) {
                 <div class="flex-grow-1">
                     <div class="d-flex justify-content-between align-items-start">
                         <div>
-                        <a href="/plan/${p.id}" class="fw-bold text-decoration-none">${p.created_at ? p.created_at.substring(0, 16) : '未知'}</a>
+                            <a href="/plan/${p.id}" class="fw-bold text-decoration-none">${formatDate(entry.date)}</a>
                             ${p.is_typical ? '<span class="badge bg-warning text-dark ms-1">典型</span>' : ''}
                         </div>
                         <button class="btn btn-sm btn-outline-danger" onclick="deletePlan(${p.id})">
@@ -511,13 +600,14 @@ function renderPlanList(plans) {
                         ${p.template_name ? ' | 模板: ' + p.template_name : ''}
                     </div>
                 </div>
-        </div>
-    `).join('');
+            </div>`;
+        }
+    }).join('');
 }
 
 async function toggleTypical(planId) {
     await fetch(`/api/plans/${planId}/typical`, {method: 'POST'});
-    loadPlans();
+    loadTimeline();
 }
 
 function showEditStudentModal() {