fix(maps): 战略地图写通道乐观并发 + 画布自动保存仅脏时写

生产缺陷 cma-strategy-map-autosave-stale-overwrite（D4 批次 19 行 map_objectives 被过期快照覆写）：
- 后端 update_map: 覆写 dimensions/canvas_data 须带 base_updated_at，与服务端 updated_at 不符 → 409；
  校验在任何写入之前完成（校验不过时一行都不删/不改）
- 连线写通道（POST/DELETE connections）响应补 updated_at，供前端采纳新基准、避免自伤 409
- 前端 MapCanvas: 自动保存仅在 draft + isDirty 时触发；请求体带 base_updated_at；收到 409 停自动保存不重试
- 修复 async onMounted 竞态：await 期间被卸载后其续段仍注册定时器（清理钩子先跑完、无人回收）
  → 泄漏写者永久在后台用过期快照覆写（生产 referer=/maps 仍每 30–60s 写）。加 disposed 守卫 + stopAutoSave
- 测试: backend/tests/test_map_concurrency_20261012.py（8 例，改前 5 败）；前端行为台架 11/11（改前 3/11）

任务: yanxue-20261012-cma-map-autosave-stale-overwrite-defect-fullstack

frontend/src/views/MapCanvas.vue

@@ -218,6 +218,10 @@ const selectedMap = ref<number | null>(null)
 const currentMap = ref<any>(null)
 const isDirty = ref(false)
 const { markDirty, markClean } = useFormGuard(isDirty)
+// 乐观并发基准（缺陷修复 2026-10-12）：本地快照对应的服务端 updated_at
+const baseUpdatedAt = ref<string | null>(null)
+// 收到 409（服务端已被他人修改）后置位：停止自动保存，绝不重试覆写
+const autoSaveBlocked = ref(false)
 const allKpis = ref<any[]>([])
 const kpiNameMap = reactive<Record<string, string>>({})
 
@@ -489,6 +493,9 @@ function loadCanvas() {
     const data = r.data || []
     const map = data.find((m: any) => m.id === selectedMap.value)
     currentMap.value = map
+    // 并发基准：本地快照对应服务端 updated_at（后续保存须带此基准）
+    baseUpdatedAt.value = map?.updated_at || null
+    autoSaveBlocked.value = false
     if (map?.dimensions) {
       for (const dim of map.dimensions) {
         dimensions.push({
@@ -514,6 +521,7 @@ function loadCanvas() {
     })
   }).catch(() => {
     ensureFourLayers()
+    baseUpdatedAt.value = null   // 载入失败 ⇒ 无基准（服务端 fail-closed）
     loading.value = false
   })
 }
@@ -579,7 +587,8 @@ function completeConnection(fromKey: string, toKey: string) {
   }
   api.post(`/maps/${selectedMap.value}/connections`, {
     from: fromKey, to: toKey,
-  }).then(() => {
+  }).then((r: any) => {
+    if (r?.updated_at) baseUpdatedAt.value = r.updated_at   // 服务端已写 ⇒ 采纳新基准（防自伤 409）
     ElMessage.success("连线已添加")
     connections.value.push({ from: fromKey, to: toKey, style: "solid", effect: "positive", label: "" })
     markDirty()
@@ -724,7 +733,8 @@ async function onManagerAddConnection(payload: { from: string; to: string; effec
     ElMessage.warning('已存在相同连线'); return
   }
   try {
-    await api.post(`/maps/${selectedMap.value}/connections`, { from: payload.from, to: payload.to })
+    const r: any = await api.post(`/maps/${selectedMap.value}/connections`, { from: payload.from, to: payload.to })
+    if (r?.updated_at) baseUpdatedAt.value = r.updated_at   // 服务端已写 ⇒ 采纳新基准（防自伤 409）
     connections.value.push({ from: payload.from, to: payload.to, style: 'solid', effect: payload.effect || 'positive', label: '' })
     markDirty()
     ElMessage.success('连线已添加')
@@ -744,7 +754,10 @@ function onManagerDeleteConnection(idx: number) {
   const conn = connections.value[idx]
   if (!conn) return
   api.delete(`/maps/${selectedMap.value}/connections`, { data: { from: conn.from, to: conn.to } })
-    .then(() => { connections.value.splice(idx, 1); nextTick(triggerRecalc) })
+    .then((r: any) => {
+      if (r?.updated_at) baseUpdatedAt.value = r.updated_at
+      connections.value.splice(idx, 1); nextTick(triggerRecalc)
+    })
     .catch(() => { connections.value.splice(idx, 1); nextTick(triggerRecalc) })
 }
 function onManagerUpdateConnection(idx: number, patch: any) {
@@ -764,7 +777,8 @@ function onDeleteConnection(idx: number) {
   if (!conn) return
   api.delete(`/maps/${selectedMap.value}/connections`, {
     data: { from: conn.from, to: conn.to },
-  }).then(() => {
+  }).then((r: any) => {
+    if (r?.updated_at) baseUpdatedAt.value = r.updated_at
     ElMessage.success("连线已删除")
     connections.value.splice(idx, 1)
     selectedConnIdx.value = null
@@ -1066,6 +1080,14 @@ function migrateOldKpiFormat() {
 let saveTimer: ReturnType<typeof setTimeout> | null = null
 let autoSaveTimer: ReturnType<typeof setInterval> | null = null
 let isSaving = false
+// 组件销毁标记（缺陷修复 2026-10-12）: onMounted 是 async —— await 期间若已卸载，
+// 其后续代码仍会执行并把定时器注册到「已销毁」的实例上（清理钩子早已跑完、无人回收），
+// 于是该定时器永久在后台用过期快照覆写服务端（生产实测：离开画布页后仍每 30–60s 写一次）。
+let disposed = false
+
+function stopAutoSave() {
+  if (autoSaveTimer) { clearInterval(autoSaveTimer); autoSaveTimer = null }
+}
 
 function debouncedSaveCanvas() {
   if (isSaving) return
@@ -1073,8 +1095,13 @@ function debouncedSaveCanvas() {
   saveTimer = setTimeout(() => { saveCanvas() }, 500)
 }
 
+// 服务端基准（乐观并发）：本地快照对应的 updated_at。null ⇒ 不带基准，服务端 fail-closed 409。
+function currentBaseStamp(): string | undefined {
+  return baseUpdatedAt.value || undefined
+}
+
 async function saveCanvas(silent?: boolean) {
-  if (!selectedMap.value) return
+  if (!selectedMap.value || disposed) return
   if (isSaving) return
   isSaving = true
   const mapData = dimensions.map((d: any) => ({
@@ -1082,16 +1109,21 @@ async function saveCanvas(silent?: boolean) {
     objectives: d.objectives,
   }))
   try {
-    await mapApi.update(selectedMap.value, {
+    const res: any = await mapApi.update(selectedMap.value, {
       dimensions: mapData,
       canvas_data: { connections: connections.value },
       version: currentMap.value?.version,
+      base_updated_at: currentBaseStamp(),   // 并发基准：过期则由服务端 409 拒绝覆写
     })
+    if (res?.updated_at) baseUpdatedAt.value = res.updated_at   // 采纳服务端新基准
     markClean()
     if (!silent) ElMessage.success("已保存")
   } catch (e: any) {
     if (e?.response?.status === 409) {
-      ElMessage.warning("地图已被修改，刷新后重试")
+      // 服务端已被他人修改：停止自动保存且不重试覆写（防过期快照整表覆写）
+      autoSaveBlocked.value = true
+      stopAutoSave()
+      ElMessage.warning("地图已被他人修改，自动保存已停止，请刷新页面后重试")
     } else {
       console.error("saveCanvas error:", e)
     }
@@ -1101,12 +1133,20 @@ async function saveCanvas(silent?: boolean) {
 }
 
 async function saveConnections() {
-  if (!selectedMap.value) return
+  if (!selectedMap.value || disposed) return
   try {
-    await mapApi.update(selectedMap.value, {
+    const res: any = await mapApi.update(selectedMap.value, {
       canvas_data: { connections: connections.value },
+      base_updated_at: currentBaseStamp(),
     })
-  } catch { /* silent */ }
+    if (res?.updated_at) baseUpdatedAt.value = res.updated_at
+  } catch (e: any) {
+    if (e?.response?.status === 409) {
+      autoSaveBlocked.value = true
+      stopAutoSave()
+      ElMessage.warning("地图已被他人修改，请刷新页面后重试")
+    }
+  }
 }
 
 // ── 发布/版本 ──
@@ -1347,10 +1387,16 @@ onMounted(async () => {
   for (const kpi of allKpis.value) {
     if (kpi.kpi_code) kpiNameMap[kpi.kpi_code] = kpi.kpi_name || kpi.kpi_code
   }
-  // 自动保存：每30秒自动保存草稿
-  autoSaveTimer = setInterval(() => {
-    if (currentMap.value?.status === 'draft') saveCanvas(true)
-  }, 30000)
+  // 自动保存：仅在「草稿 + 本地有未保存变更(isDirty) + 未被 409 停写 + 未销毁」时写入
+  // （缺陷修复 2026-10-12：原来无条件每 30s 用本地快照整表覆写，会回置他方写入）
+  if (!disposed) {
+    autoSaveTimer = setInterval(() => {
+      if (disposed || autoSaveBlocked.value) return
+      if (currentMap.value?.status === 'draft' && isDirty.value) saveCanvas(true)
+    }, 30000)
+    // 注册/销毁竞态兜底：若 await 期间已被卸载，立即回收
+    if (disposed) stopAutoSave()
+  }
   nextTick(() => {
     updateGridMode()
     updateZoomWrapHeight()
@@ -1360,10 +1406,11 @@ onMounted(async () => {
 })
 
 onUnmounted(() => {
+  disposed = true   // 先置位：阻断仍在 await 中的 onMounted 续段再注册定时器（防泄漏）
   scrollWrapRef.value?.removeEventListener('scroll', onCanvasScroll)
   window.removeEventListener('resize', onWindowResize)
   if (saveTimer) clearTimeout(saveTimer)
-  if (autoSaveTimer) clearInterval(autoSaveTimer)
+  stopAutoSave()
 })
 </script>