feat: refactor monolithic App.vue into modular Vue component architecture

- Extract 711-line App.vue into 15+ focused files across 5 directories
- Add data layer (icons, metrics, policies, auditTrail, requests)
- Add composables (useNavigation, useRequests, useChat, useToast)
- Add layout components (SidebarRail, TopBar, FilterBar)
- Add shared components (PanelHead, InfoRow, ToastNotification)
- Add business component (RequestTable) and 5 view components
- Extract global CSS to assets/styles/global.css
- Add start.sh with WSL/Windows cross-platform support
- Add .gitignore for node_modules, dist, and IDE dirs

src/data/requests.js

@@ -0,0 +1,14 @@
+export const initialRequests = [
+  { id: 'REQ-2026-0418', person: '刘倩', dept: '销售 · 华东区域', category: '差旅报销', amount: '¥8,460', verdict: '可通过但需备注', status: 'warning', sla: '51h', risk: '住宿超标 17.4%' },
+  { id: 'REQ-2026-0422', person: '韩阳', dept: '解决方案 · 北区', category: '业务招待', amount: '¥1,980', verdict: '等待补件', status: 'warning', sla: '22h', risk: '缺少客户拜访纪要' },
+  { id: 'REQ-2026-0431', person: '王鑫', dept: '运营管理 · 总部', category: '通勤交通', amount: '¥1,224', verdict: '规则全通过', status: 'success', sla: '4h', risk: '无明显风险' },
+  { id: 'REQ-2026-0436', person: '陈嘉', dept: '市场 · 品牌活动', category: '活动采购', amount: '¥12,680', verdict: '建议人工复核', status: 'danger', sla: '36h', risk: '供应商与历史黑名单相似' }
+]
+
+export const prompts = ['生成审批意见', '列出补件清单', '解释为什么拦截', '生成审计摘要']
+
+export const initialMessages = [
+  { id: 1, role: 'agent', text: '我已读取单据、发票、行程和公司差旅制度。当前建议：可通过，但需要保留会议说明。' },
+  { id: 2, role: 'user', text: '请列出这张单据的主要风险。' },
+  { id: 3, role: 'agent', text: '主要风险：住宿单晚均价超标准 17.4%，并且需要人工确认会议附件。' }
+]