Fix CI build failure and upgrade Gradle to 9.1.0

- Add duplicate handling strategy to processResources task to resolve
  CycloneDX BOM plugin conflict causing build failures
- Upgrade Gradle wrapper from 8.12 to 9.1.0
- Update minimum Gradle version requirement in documentation

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: pacphi

build.gradle

@@ -43,6 +43,10 @@ dependencyManagement {
 	}
 }
 
+processResources {
+    duplicatesStrategy = DuplicatesStrategy.INCLUDE
+}
+
 bootRun {
     systemProperties System.properties
 }

docs/TOOLS.md

@@ -3,7 +3,7 @@
 ## Tools
 
 * [sdkman](https://sdkman.io) 5.8.12 or better
-* [Gradle](https://docs.gradle.org/current/userguide/installation.html) 8.10 or better
+* [Gradle](https://docs.gradle.org/current/userguide/installation.html) 9.1.0 or better
 * [JDK](http://openjdk.java.net/install/) 21 or better
 * [git](https://git-scm.com/downloads) 2.40.0 or better
 * [gh](https://github.com/cli/cli) 2.42.0 or better

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.12-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.1.0-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME