Add g and kg catalog filters

app/page.tsx

@@ -94,6 +94,46 @@ function getCategoryCount(category: string) {
   return category === SILENT_SERVO_CATEGORY ? SILENT_SERVO_COUNT : CATALOG_COUNTS[category];
 }
 
+type ProductScale = {
+  key: string;
+  label: string;
+  unit: "g" | "kg";
+  value: number;
+};
+
+function getProductScale(product: CatalogProduct): ProductScale | null {
+  const kilogramMatch = product.name.match(/(\d+(?:\.\d+)?)\s*(?:kg|千克)/i);
+  if (kilogramMatch) {
+    const value = Number(kilogramMatch[1]);
+    return { key: `kg:${value}`, label: `${value}kg`, unit: "kg", value };
+  }
+
+  const gramMatch = product.name.match(/(\d+(?:\.\d+)?)\s*(?:g|克)/i);
+  if (gramMatch) {
+    const value = Number(gramMatch[1]);
+    return { key: `g:${value}`, label: `${value}g`, unit: "g", value };
+  }
+
+  return null;
+}
+
+const PRODUCT_SCALE_OPTIONS = [...CATALOG_PRODUCTS.reduce((options, product) => {
+  const scale = getProductScale(product);
+  if (!scale) return options;
+  const current = options.get(scale.key);
+  options.set(scale.key, { ...scale, count: (current?.count ?? 0) + 1 });
+  return options;
+}, new Map<string, ProductScale & { count: number }>()).values()].sort(
+  (a, b) => (a.unit === b.unit ? a.value - b.value : a.unit === "g" ? -1 : 1),
+);
+
+const GRAM_SCALE_OPTIONS = PRODUCT_SCALE_OPTIONS.filter((option) => option.unit === "g");
+const KILOGRAM_SCALE_OPTIONS = PRODUCT_SCALE_OPTIONS.filter((option) => option.unit === "kg");
+const UNMARKED_SCALE_COUNT = CATALOG_PRODUCTS.length - PRODUCT_SCALE_OPTIONS.reduce(
+  (total, option) => total + option.count,
+  0,
+);
+
 function inferWeight(product: CatalogProduct) {
   const listedWeight = parseNumbers(product.specs["重量"])[0];
   if (Number.isFinite(listedWeight)) return listedWeight;
@@ -280,6 +320,7 @@ export default function Home() {
   const [leadId, setLeadId] = useState("");
   const [catalogQuery, setCatalogQuery] = useState("");
   const [catalogCategory, setCatalogCategory] = useState("全部产品");
+  const [catalogScale, setCatalogScale] = useState("all");
   const [catalogLimit, setCatalogLimit] = useState(24);
   const [selectedCatalogProduct, setSelectedCatalogProduct] = useState<CatalogProduct | null>(null);
 
@@ -290,6 +331,8 @@ export default function Home() {
   const filteredCatalog = useMemo(() => {
     const query = catalogQuery.trim().toLowerCase();
     return CATALOG_PRODUCTS.filter((product) => {
+      const productScale = getProductScale(product)?.key ?? "unmarked";
+      if (catalogScale !== "all" && productScale !== catalogScale) return false;
       const matchesCategory =
         catalogCategory === "全部产品" ||
         product.category === catalogCategory ||
@@ -307,7 +350,7 @@ export default function Home() {
         .toLowerCase();
       return haystack.includes(query);
     });
-  }, [catalogCategory, catalogQuery]);
+  }, [catalogCategory, catalogQuery, catalogScale]);
   const visibleCatalog = filteredCatalog.slice(0, catalogLimit);
   const needsEngineer =
     !top?.coreCompatible ||
@@ -894,6 +937,32 @@ export default function Home() {
               >{category === SILENT_SERVO_CATEGORY ? `${category} · ${SILENT_SERVO_COUNT}` : category}</button>
             ))}
           </div>
+          <div className="catalog-scale-filter">
+            <label>
+              <span>按 g / kg 型号规格筛选</span>
+              <select
+                value={catalogScale}
+                onChange={(event) => {
+                  setCatalogScale(event.target.value);
+                  setCatalogLimit(24);
+                }}
+              >
+                <option value="all">全部 g / kg 规格</option>
+                <optgroup label="克重系列（g / 克）">
+                  {GRAM_SCALE_OPTIONS.map((option) => (
+                    <option key={option.key} value={option.key}>{option.label}（{option.count}款）</option>
+                  ))}
+                </optgroup>
+                <optgroup label="千克扭矩等级（kg / 千克）">
+                  {KILOGRAM_SCALE_OPTIONS.map((option) => (
+                    <option key={option.key} value={option.key}>{option.label}（{option.count}款）</option>
+                  ))}
+                </optgroup>
+                <option value="unmarked">其他未标注 g/kg（{UNMARKED_SCALE_COUNT}款）</option>
+              </select>
+            </label>
+            <p><strong>说明：</strong>g/克表示产品克重系列；kg/Kg通常表示舵机扭矩等级，并非产品自身重量。</p>
+          </div>
           <p className="catalog-result-count">
             找到 <strong>{filteredCatalog.length}</strong> 个型号
           </p>
@@ -936,7 +1005,7 @@ export default function Home() {
           <div className="catalog-empty">
             <strong>没有找到匹配型号</strong>
             <p>可以尝试减少关键词，或切换到“全部产品”。</p>
-            <button type="button" onClick={() => { setCatalogQuery(""); setCatalogCategory("全部产品"); }}>
+            <button type="button" onClick={() => { setCatalogQuery(""); setCatalogCategory("全部产品"); setCatalogScale("all"); }}>
               清除筛选
             </button>
           </div>