feat: 新增嵌入式分布式调度底座

- 提供通用调度 API、Quartz JDBC Provider 与独立 Starter

- 补充 MySQL、PostgreSQL、H2 建表脚本与接入校验

- 同步完善 Federation 与 Scheduler 模块说明

easy-agents-scheduler/easy-agents-scheduler-core/pom.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>com.easyagents</groupId>
+        <artifactId>easy-agents-scheduler</artifactId>
+        <version>${revision}</version>
+    </parent>
+
+    <artifactId>easy-agents-scheduler-core</artifactId>
+    <name>easy-agents-scheduler-core</name>
+
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>