fix(resource-cache): resolve DataFrame TTL eviction causing empty resource status

_records_from_index() returned [] when process-level DataFrame cache (30s TTL)
expired but derived index remained ready=true. Now reloads from Redis via
_get_cached_data() instead of returning empty.

Also rename /resource page from "機台狀態" to "設備即時概況" in page_status.json.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

data/page_status.json

@@ -45,7 +45,7 @@
     },
     {
       "route": "/resource",
-      "name": "機台狀態",
+      "name": "設備即時概況",
       "status": "released",
       "drawer_id": "reports",
       "order": 2

src/mes_dashboard/services/resource_cache.py

@@ -419,7 +419,11 @@ def _records_from_index(index: ResourceIndex, positions: list[RowPosition] | Non
                 return list(legacy_records)
             selected = [legacy_records[int(pos)] for pos in positions if 0 <= int(pos) < len(legacy_records)]
             return selected
-        return []
+        # DataFrame evicted from process cache (TTL expired) and no legacy
+        # records stored in index.  Reload from Redis before giving up.
+        df = _get_cached_data()
+        if df is None:
+            return []
     selected_positions = positions if positions is not None else index.get("all_positions", [])
     if not selected_positions:
         selected_positions = list(range(len(df)))