feat: 改造为冷轧双机架二级控制系统

- 删除 ruoyi-flowable 模块，移除所有 Flowable 依赖
- 新建 ruoyi-mill 业务模块：
  * protocol: iXComPCS UDP 电文编解码器（7条电文完整定义）
  * udp: UdpServer/UdpSender/TelegramDispatcher
  * domain: MillPlan / MillProductionResult
  * service/controller: 生产计划、产出管理骨架
- 前端改造为工业深色主题（深海军蓝 + 工业青色）
- 系统标题更新为"冷轧双机架二级控制系统"
- application.yml 新增 mill.udp 配置节

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

pom.xml

@@ -35,7 +35,6 @@
         <logback.version>1.2.13</logback.version>
         <spring-security.version>5.7.12</spring-security.version>
         <spring-framework.version>5.3.39</spring-framework.version>
-        <flowable.version>6.8.0</flowable.version>
     </properties>
 
     <!-- 依赖声明 -->
@@ -219,17 +218,13 @@
                 <version>${ruoyi.version}</version>
             </dependency>
 
+            <!-- 冷轧业务模块-->
             <dependency>
                 <groupId>com.ruoyi</groupId>
-                <artifactId>ruoyi-flowable</artifactId>
+                <artifactId>ruoyi-mill</artifactId>
                 <version>${ruoyi.version}</version>
             </dependency>
 
-            <dependency>
-                <groupId>org.flowable</groupId>
-                <artifactId>flowable-spring-boot-starter</artifactId>
-                <version>${flowable.version}</version>
-            </dependency>
             <dependency>
                 <groupId>io.swagger</groupId>
                 <artifactId>swagger-annotations</artifactId>
@@ -252,7 +247,7 @@
         <module>ruoyi-quartz</module>
         <module>ruoyi-generator</module>
         <module>ruoyi-common</module>
-        <module>ruoyi-flowable</module>
+        <module>ruoyi-mill</module>
     </modules>
     <packaging>pom</packaging>