移除城市快捷跳转栏 sticky 固定效果，更新 LGBM 模型至 1247 样本

scan-ai-city-jumpbar 不再吸附顶部，anchor scroll-margin 同步清理。
LGBM 模型用 prod DB 重训练：1247 样本 → 验证 MAE 2.63°C vs DEB 2.75°C。

Tested: tsc + ruff 全过

artifacts/models/lgbm_daily_high_schema.json

@@ -42,25 +42,25 @@
     "nws"
   ],
   "model_path": "artifacts\\models\\lgbm_daily_high.txt",
-  "sample_count": 20,
+  "sample_count": 1247,
-  "train_count": 8,
+  "train_count": 998,
-  "validation_count": 12,
+  "validation_count": 249,
   "metrics": {
     "validation": {
-      "sample_count": 12,
+      "sample_count": 249,
-      "lgbm_mae": 5.867,
+      "lgbm_mae": 2.626,
-      "deb_mae": 1.825,
+      "deb_mae": 2.745,
-      "best_single_mae": 0.567,
+      "best_single_mae": 1.733,
-      "median_mae": 1.7
+      "median_mae": 2.866
     },
     "full_sample": {
-      "sample_count": 20,
+      "sample_count": 1247,
-      "lgbm_mae": 2.66,
+      "lgbm_mae": 0.953,
-      "deb_mae": 1.68,
+      "deb_mae": 1.872,
-      "best_single_mae": 0.775,
+      "best_single_mae": 1.052,
-      "median_mae": 1.695
+      "median_mae": 1.952
     }
   },
-  "generated_at": "2026-04-18T19:27:39.228210Z",
+  "generated_at": "2026-05-06T10:45:04.319587Z",
-  "trained_at": "2026-04-18T19:27:39.228210Z"
+  "trained_at": "2026-05-06T10:45:04.319587Z"
 }

frontend/components/dashboard/ScanTerminalList.module.css

@@ -545,9 +545,6 @@
 }
 
 .root :global(.scan-ai-city-jumpbar) {
-  position: sticky;
-  top: 0;
-  z-index: 8;
   display: flex;
   gap: 8px;
   margin: 0 0 12px;
@@ -583,9 +580,6 @@
   background: rgba(77, 163, 255, 0.18);
 }
 
-.root :global(.scan-ai-city-anchor) {
-  scroll-margin-top: 66px;
-}
 
 .root :global(.scan-ai-city-card:not(.collapsed)) {
   overflow: visible;