Merge branch 'master' into feature/ext-scheduler/cron-and-interval-jobs

Resolve conflicts in AGENTS.md, pom.xml and flash-extensions/pom.xml — master
had already picked up ext-validation and ext-cache-core/caffeine (merged after
this branch was cut); union kept alongside this branch's ext-scheduler entries.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

pom.xml

@@ -38,6 +38,8 @@
         <maven.versions.plugin.version>2.18.0</maven.versions.plugin.version>
         <jmh.version>1.37</jmh.version>
         <junit.version>5.11.0</junit.version>
+        <caffeine.version>3.1.8</caffeine.version>
+        <jakarta.validation.version>3.1.1</jakarta.validation.version>
         <build.helper.plugin.version>3.6.0</build.helper.plugin.version>
     </properties>
 
@@ -67,11 +69,31 @@
                 <artifactId>flash-testing</artifactId>
                 <version>${project.version}</version>
             </dependency>
+            <dependency>
+                <groupId>dev.relism</groupId>
+                <artifactId>flash-ext-validation</artifactId>
+                <version>${project.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>jakarta.validation</groupId>
+                <artifactId>jakarta.validation-api</artifactId>
+                <version>${jakarta.validation.version}</version>
+            </dependency>
             <dependency>
                 <groupId>dev.relism</groupId>
                 <artifactId>flash-ext-scheduler</artifactId>
                 <version>${project.version}</version>
             </dependency>
+            <dependency>
+                <groupId>dev.relism</groupId>
+                <artifactId>flash-ext-cache-core</artifactId>
+                <version>${project.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>dev.relism</groupId>
+                <artifactId>flash-ext-cache-caffeine</artifactId>
+                <version>${project.version}</version>
+            </dependency>
             <dependency>
                 <groupId>dev.relism</groupId>
                 <artifactId>flash-ext-jackson</artifactId>