feat: 支持指针模式复制粘贴、Markdown 链接渲染与多项优化

- 移除 Google Fonts 依赖，改用系统字体栈（优化国内访问）
- 指针模式下支持 Ctrl+C / Ctrl+V 复制粘贴选中便签与分组（自动重映射分组归属、偏移 24px 放置）
- 卡片渲染 Markdown 描述（marked + DOMPurify 消毒），新增「关联链接」按钮显示 link 字段
- 里程碑卡补渲染标签
- 忽略 *.tsbuildinfo 构建产物

frontend/src/components/dashboard/MetricCard.vue

@@ -3,6 +3,8 @@ import type { ParsedNote } from '@/types/card'
 import { computed } from 'vue'
 import StatusBadge from '@/components/shared/StatusBadge.vue'
 import PriorityBadge from '@/components/shared/PriorityBadge.vue'
+import CardLink from '@/components/shared/CardLink.vue'
+import { renderMarkdown } from '@/utils/md'
 
 const props = defineProps<{
   card: ParsedNote
@@ -46,7 +48,10 @@ const achievementColor = computed(() => {
         />
       </div>
     </div>
-    <p class="metric-desc" v-if="card.description">{{ card.description }}</p>
+    <p class="metric-desc" v-if="card.description" v-html="renderMarkdown(card.description)" />
+    <div class="metric-link" v-if="card.link">
+      <CardLink :url="card.link" />
+    </div>
   </div>
 </template>
 
@@ -133,4 +138,28 @@ const achievementColor = computed(() => {
   margin-top: 12px;
   text-align: center;
 }
+
+.metric-link {
+  display: flex;
+  justify-content: center;
+  margin-top: 10px;
+}
+
+.metric-desc :deep(a) {
+  color: var(--accent);
+  text-decoration: none;
+  word-break: break-all;
+}
+
+.metric-desc :deep(a:hover) {
+  text-decoration: underline;
+}
+
+.metric-desc :deep(strong) {
+  color: var(--text-primary);
+}
+
+.metric-desc :deep(p) {
+  margin: 4px 0;
+}
 </style>

frontend/src/components/dashboard/MilestoneCard.vue

@@ -4,6 +4,8 @@ import { computed } from 'vue'
 import ProgressBar from '@/components/shared/ProgressBar.vue'
 import StatusBadge from '@/components/shared/StatusBadge.vue'
 import PriorityBadge from '@/components/shared/PriorityBadge.vue'
+import CardLink from '@/components/shared/CardLink.vue'
+import { renderMarkdown } from '@/utils/md'
 
 const props = defineProps<{
   card: ParsedNote
@@ -54,7 +56,13 @@ const progress = computed(() => {
       </div>
       <p class="milestone-date">{{ card.deadline || '无截止日期' }}</p>
       <ProgressBar v-if="progress !== null" :value="progress" :status="card.status || undefined" />
-      <p class="milestone-desc" v-if="card.description">{{ card.description }}</p>
+      <div class="milestone-tags" v-if="card.tags.length > 0">
+        <span class="tag" v-for="tag in card.tags.slice(0, 5)" :key="tag">{{ tag }}</span>
+      </div>
+      <p class="milestone-desc" v-if="card.description" v-html="renderMarkdown(card.description)" />
+      <div class="milestone-link" v-if="card.link">
+        <CardLink :url="card.link" />
+      </div>
     </div>
   </div>
 </template>
@@ -104,9 +112,47 @@ const progress = computed(() => {
   margin-bottom: 8px;
 }
 
+.milestone-tags {
+  display: flex;
+  gap: 4px;
+  flex-wrap: wrap;
+  margin-bottom: 4px;
+}
+
+.milestone-tags .tag {
+  font-size: 11px;
+  padding: 2px 8px;
+  border-radius: 10px;
+  background: var(--accent-soft);
+  color: var(--accent);
+  font-weight: 500;
+}
+
 .milestone-desc {
   font-size: 13px;
   color: var(--text-secondary);
   margin-top: 8px;
 }
+
+.milestone-link {
+  margin-top: 8px;
+}
+
+.milestone-desc :deep(a) {
+  color: var(--accent);
+  text-decoration: none;
+  word-break: break-all;
+}
+
+.milestone-desc :deep(a:hover) {
+  text-decoration: underline;
+}
+
+.milestone-desc :deep(strong) {
+  color: var(--text-primary);
+}
+
+.milestone-desc :deep(p) {
+  margin: 4px 0;
+}
 </style>

frontend/src/components/dashboard/TaskCard.vue

@@ -5,6 +5,8 @@ import { useNotesStore } from '@/stores/notes'
 import ProgressBar from '@/components/shared/ProgressBar.vue'
 import StatusBadge from '@/components/shared/StatusBadge.vue'
 import PriorityBadge from '@/components/shared/PriorityBadge.vue'
+import CardLink from '@/components/shared/CardLink.vue'
+import { renderMarkdown } from '@/utils/md'
 
 const props = defineProps<{
   card: ParsedNote
@@ -91,8 +93,10 @@ async function toggleSubTask(index: number) {
       :status="card.status || undefined"
     />
 
-    <div class="card-description" v-if="card.description">
-      {{ card.description }}
+    <div class="card-description md-body" v-if="card.description" v-html="renderMarkdown(card.description)" />
+
+    <div class="card-link-row" v-if="card.link">
+      <CardLink :url="card.link" />
     </div>
 
     <ul class="subtask-list" v-if="card.subTasks.length > 0">
@@ -195,6 +199,31 @@ async function toggleSubTask(index: number) {
   overflow: hidden;
 }
 
+.card-link-row {
+  display: flex;
+  align-items: center;
+  margin: 12px 0;
+}
+
+.md-body :deep(a) {
+  color: var(--accent);
+  text-decoration: none;
+  word-break: break-all;
+}
+
+.md-body :deep(a:hover) {
+  text-decoration: underline;
+}
+
+.md-body :deep(strong) {
+  color: var(--text-primary);
+  font-weight: 600;
+}
+
+.md-body :deep(p) {
+  margin: 4px 0;
+}
+
 .subtask-list {
   list-style: none;
   margin: 12px 0;