fix(frontend): 修复合并审阅发现的构建与契约问题

恢复 Vue TypeScript 生产构建，补齐可运行页面壳子，并修复文件树与 SSE 状态问题。

按 FastAPI Wire Contract 统一 Service DTO 映射，同时补充前端开发说明和问题修复复盘。

frontend/src/services/noteService.ts

@@ -1,38 +1,39 @@
 import apiClient from './apiClient'
-import type { Note, NoteBlock } from '@/contracts'
+import type { ApiNote, ApiNoteSummary, OperationResponse, PageMeta } from '@/contracts'
 
 export async function listNotes(params?: {
   folder?: string
   tag?: string
   limit?: number
   offset?: number
-}): Promise<{ items: Note[]; total: number }> {
+}): Promise<{ items: ApiNoteSummary[]; page: PageMeta }> {
   return apiClient.get('/api/notes', { params })
 }
 
-export async function getNote(noteId: string): Promise<{ note: Note; blocks: NoteBlock[] }> {
+export async function getNote(noteId: string): Promise<ApiNote> {
   return apiClient.get(`/api/notes/${noteId}`)
 }
 
 export async function createNote(data: {
   title: string
-  folder_path?: string
-  content?: string
-}): Promise<Note> {
+  folder?: string
+  markdown?: string
+  tags?: string[]
+}): Promise<ApiNote> {
   return apiClient.post('/api/notes', data)
 }
 
 export async function updateNote(
   noteId: string,
-  data: { title?: string; content?: string; tags?: string[] }
-): Promise<Note> {
+  data: { title?: string; markdown?: string; tags?: string[] }
+): Promise<ApiNote> {
   return apiClient.patch(`/api/notes/${noteId}`, data)
 }
 
-export async function deleteNote(noteId: string): Promise<void> {
+export async function deleteNote(noteId: string): Promise<OperationResponse> {
   return apiClient.delete(`/api/notes/${noteId}`)
 }
 
-export async function moveNote(noteId: string, target_folder: string): Promise<Note> {
-  return apiClient.post(`/api/notes/${noteId}/move`, { target_folder })
+export async function moveNote(noteId: string, folder: string): Promise<ApiNote> {
+  return apiClient.post(`/api/notes/${noteId}/move`, { folder })
 }