feat: 准实时同步（变更 3 秒推送 + SSE 秒级拉取）并修复云端认证

server/index.js

@@ -76,6 +76,24 @@ function base64url(s) {
   return Buffer.from(s).toString('base64url')
 }
 
+// ---------- SSE 长连接：按用户分组，数据变更时实时通知 ----------
+const sseClients = new Map()
+function broadcast(userId, event) {
+  const set = sseClients.get(userId)
+  if (!set) return
+  for (const res of set) {
+    try { res.write('event: ' + event + '\ndata: {}\n\n') } catch { /* 连接已断开 */ }
+  }
+}
+function addSse(userId, res) {
+  if (!sseClients.has(userId)) sseClients.set(userId, new Set())
+  sseClients.get(userId).add(res)
+}
+function removeSse(userId, res) {
+  const set = sseClients.get(userId)
+  if (set) { set.delete(res); if (!set.size) sseClients.delete(userId) }
+}
+
 // ---------- HTTP 基础 ----------
 function json(res, status, data) {
   const body = JSON.stringify(data)
@@ -113,6 +131,25 @@ async function handle(req, res) {
 
   if (req.method === 'GET' && route === '/api/health') { json(res, 200, { ok: true }); return }
 
+  // SSE 事件流：token 经查询参数传递（EventSource 无法自定义请求头）
+  if (req.method === 'GET' && route === '/api/events') {
+    const auth = verifyToken(url.searchParams.get('token'))
+    if (!auth) { json(res, 401, { error: '未认证' }); return }
+    res.writeHead(200, {
+      'Content-Type': 'text/event-stream',
+      'Cache-Control': 'no-cache',
+      Connection: 'keep-alive',
+      'Access-Control-Allow-Origin': '*'
+    })
+    res.write('event: hello\ndata: {}\n\n')
+    addSse(auth.userId, res)
+    const ka = setInterval(() => {
+      try { res.write(': keepalive\n\n') } catch { /* 忽略 */ }
+    }, 25000)
+    req.on('close', () => { clearInterval(ka); removeSse(auth.userId, res) })
+    return
+  }
+
   if (req.method === 'POST' && route === '/api/auth/register') {
     const body = await readBody(req)
     const username = String(body.username || '').trim()
@@ -149,6 +186,7 @@ async function handle(req, res) {
 
     // 应用推送的变更（新者胜）
     const incomingTables = body.tables || {}
+    let changed = 0
     for (const t of TABLES) {
       const rows = incomingTables[t] || []
       userData.tables[t] = userData.tables[t] || {}
@@ -159,6 +197,7 @@ async function handle(req, res) {
         const existing = userData.tables[t][row.uuid]
         if (!existing || String(clean.updated_at || '') >= String(existing.updated_at || '')) {
           userData.tables[t][row.uuid] = clean
+          changed++
         }
       }
     }
@@ -168,7 +207,10 @@ async function handle(req, res) {
       if (!TABLES.includes(tb.table) || !tb.uuid) continue
       userData.tombstones[tb.table] = userData.tombstones[tb.table] || {}
       const prev = userData.tombstones[tb.table][tb.uuid]
-      if (!prev || tb.deleted_at > prev) userData.tombstones[tb.table][tb.uuid] = tb.deleted_at
+      if (!prev || tb.deleted_at > prev) {
+        userData.tombstones[tb.table][tb.uuid] = tb.deleted_at
+        changed++
+      }
     }
     // 墓碑生效：清除被删数据
     for (const t of TABLES) {
@@ -179,6 +221,7 @@ async function handle(req, res) {
       }
     }
     saveUserData(auth.userId, userData)
+    if (changed) broadcast(auth.userId, 'change')
 
     // 返回权威全量
     const outTables = {}