diff --git a/backend/app/api/maps.py b/backend/app/api/maps.py
index feca4482..a8ec85e2 100644
--- a/backend/app/api/maps.py
+++ b/backend/app/api/maps.py
@@ -558,6 +558,8 @@ def add_connection(map_id: int, data: dict, db: Session = Depends(get_db), entit
         "label": data.get("label", ""),
     })
     m.canvas_data["connections"] = conns
+    from sqlalchemy.orm.attributes import flag_modified
+    flag_modified(m, "canvas_data")   # 同上：JSON 列需显式标脏才能落库
     db.commit()
     # updated_at: 供前端采纳为新基准（并发保护 base_updated_at），避免自伤 409
     return {"connections": conns, "updated_at": _stamp(m.updated_at)}
@@ -580,6 +582,10 @@ def delete_connection_by_key(map_id: int, data: dict, db: Session = Depends(get_
         raise HTTPException(404, "连线不存在")
 
     m.canvas_data["connections"] = new_conns
+    # JSON 列就地/换列表赋值不会被 ORM 自动标记为 dirty ⇒ 必须显式 flag_modified，
+    # 否则接口返回 200 且响应列表已减 1，但 commit 不 flush，重读仍是旧值（删连线变哑弹）。
+    from sqlalchemy.orm.attributes import flag_modified
+    flag_modified(m, "canvas_data")
     db.commit()
     return {"connections": new_conns, "removed": {"from": from_id, "to": to_id},
             "updated_at": _stamp(m.updated_at)}
diff --git a/backend/app/main.py b/backend/app/main.py
index b5c98863..e79135c3 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -40,6 +40,10 @@ app.include_router(auth.router)
 app.include_router(kpis.router)
 app.include_router(kpi_governance.router)
 app.include_router(templates.router)
+# ⚠️ 顺序要求：完备度/摘要条路由必须先于 maps/objectives 等「/{map_id}/...」通配路由注册，
+#    否则 /maps/completeness/objectives 会被 /{map_id}/objectives 抢先匹配（map_id="completeness" → 422）。
+app.include_router(map_completeness.router)  # 战略地图数据完备度（口径 CMA-CALIBER-MAP-COMPLETENESS-20261018 v1.0）
+app.include_router(map_summary.router)  # 战略地图摘要条（收入分线/新式毛利率/管理指标 · 口径 CMA-A1 终稿）
 app.include_router(maps.router)
 app.include_router(dashboard.router)
 app.include_router(data.router)
@@ -56,8 +60,6 @@ app.include_router(action_plans.router)
 app.include_router(alignment.router)
 app.include_router(org.router)
 app.include_router(objectives.router)
-app.include_router(map_completeness.router)  # 战略地图数据完备度（口径 CMA-CALIBER-MAP-COMPLETENESS-20261018 v1.0）
-app.include_router(map_summary.router)  # 战略地图摘要条（收入分线/新式毛利率/管理指标 · 口径 CMA-A1 终稿）
 app.include_router(versions.router)
 app.include_router(budget.router)
 app.include_router(value_sources.router)
diff --git a/frontend/src/views/MapCanvas.vue b/frontend/src/views/MapCanvas.vue
index 58d6420a..7aa36419 100644
--- a/frontend/src/views/MapCanvas.vue
+++ b/frontend/src/views/MapCanvas.vue
@@ -994,10 +994,21 @@ function onTreeDragStart(payload: { dimKey: string; index: number; obj: any }) {
 }
 function onTreeDragOver(e: DragEvent) {
   if (!treeDragSource.value) return
-  const el = document.elementFromPoint(e.clientX, e.clientY)?.closest('[data-node-key]') as HTMLElement | null
-  const key = el?.getAttribute('data-node-key') || null
+  // 命中判定改用节点 rect 包含判断：elementFromPoint 会被覆盖层（窄屏时的知识面板 .kp-panel、
+  // 连线 SVG 等）挡住 ⇒ 拖拽在窄屏下永远取不到目标节点。rect 判定与层级无关。
+  const key = hitTestNodeKey(e.clientX, e.clientY)
   dragConnectTarget.value = key && key !== treeDragSource.value.key ? key : null
 }
+function hitTestNodeKey(x: number, y: number): string | null {
+  const nodes = document.querySelectorAll('[data-node-key]') as NodeListOf<HTMLElement>
+  for (const el of Array.from(nodes)) {
+    const r = el.getBoundingClientRect()
+    if (r.width > 0 && r.height > 0 && x >= r.left && x <= r.right && y >= r.top && y <= r.bottom) {
+      return el.getAttribute('data-node-key')
+    }
+  }
+  return null
+}
 function onTreeDragLeave(e: DragEvent) {
   const related = (e as any).relatedTarget as Node | null
   const box = scrollWrapRef.value