优化实例搜索功能，调整CPU核心数和内存容量的最大值，确保输入更灵活，同时限制返回结果数量至40条。

backend/app/services/aws/pricing_v2.py

@@ -71,11 +71,11 @@ async def search_instances_v2(
             query += " AND area_en = %s"
             params.append(region_name)
         
-        if cpu_cores:
+        if cpu_cores > 0:
             query += " AND vcpu = %s"
             params.append(cpu_cores)
         
-        if memory_gb:
+        if memory_gb > 0:
             query += " AND memory = %s"
             params.append(memory_gb)
             
@@ -88,6 +88,9 @@ async def search_instances_v2(
         cursor.execute(query, params)
         results = cursor.fetchall()
 
+        if len(results) >= 40:
+            results = results[0:40]
+        
         # 处理结果
         instances = []
         for row in results:

frontend/src/views/InstanceSearch.vue

@@ -16,7 +16,7 @@
                 <el-input-number 
                   v-model="form.cpu_cores" 
                   :min="0" 
-                  :max="64" 
+                  :max="9999" 
                   :step="1"
                   placeholder="所需CPU核心数"
                   class="full-width">
@@ -29,7 +29,7 @@
                 <el-input-number 
                   v-model="form.memory_gb" 
                   :min="0" 
-                  :max="256" 
+                  :max="99999" 
                   :step="0.5"
                   placeholder="所需内存容量(GB)"
                   class="full-width">
@@ -388,8 +388,8 @@ export default {
   data() {
     return {
       form: {
-        cpu_cores: null,
+        cpu_cores: 0,
-        memory_gb: null,
+        memory_gb: 0,
         disk_gb: 30, // 默认30GB
         region: 'us-east-1',
         disk_type: 'gp3',