feat: 搭建后端多租户名片服务

- 初始化 Spring Boot 多模块工程与通用基础能力

- 增加租户、组织、用户、名片、文件、统计等业务模块

- 补充数据库迁移脚本与基础测试

backend/pom.xml

@@ -0,0 +1,94 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>com.easycard</groupId>
+  <artifactId>easycard-parent</artifactId>
+  <version>0.1.0-SNAPSHOT</version>
+  <packaging>pom</packaging>
+
+  <name>easycard-parent</name>
+  <description>Easycard backend parent project</description>
+
+  <modules>
+    <module>easycard-common</module>
+    <module>easycard-module-system</module>
+    <module>easycard-module-tenant</module>
+    <module>easycard-module-org</module>
+    <module>easycard-module-user</module>
+    <module>easycard-module-card</module>
+    <module>easycard-module-file</module>
+    <module>easycard-module-stat</module>
+    <module>easycard-boot</module>
+  </modules>
+
+  <properties>
+    <java.version>21</java.version>
+    <maven.compiler.release>${java.version}</maven.compiler.release>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <spring.boot.version>3.3.13</spring.boot.version>
+    <mybatis.plus.version>3.5.7</mybatis.plus.version>
+    <springdoc.version>2.6.0</springdoc.version>
+  </properties>
+
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-dependencies</artifactId>
+        <version>${spring.boot.version}</version>
+        <type>pom</type>
+        <scope>import</scope>
+      </dependency>
+
+      <dependency>
+        <groupId>com.baomidou</groupId>
+        <artifactId>mybatis-plus-spring-boot3-starter</artifactId>
+        <version>${mybatis.plus.version}</version>
+      </dependency>
+
+      <dependency>
+        <groupId>org.springdoc</groupId>
+        <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
+        <version>${springdoc.version}</version>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <version>1.18.34</version>
+      <scope>provided</scope>
+      <optional>true</optional>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-compiler-plugin</artifactId>
+          <version>3.13.0</version>
+          <configuration>
+            <release>${java.version}</release>
+            <parameters>true</parameters>
+          </configuration>
+        </plugin>
+        <plugin>
+          <groupId>org.springframework.boot</groupId>
+          <artifactId>spring-boot-maven-plugin</artifactId>
+          <version>${spring.boot.version}</version>
+        </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-surefire-plugin</artifactId>
+          <version>3.2.5</version>
+        </plugin>
+      </plugins>
+    </pluginManagement>
+  </build>
+</project>