chore: Java 26 + Gradle 9.7.0, all 20 deps updated, 1GB mem limit

- build.gradle: Gradle toolchain languageVersion 26 (auto-detects /usr/lib/jvm,
  no JAVA_HOME export needed), .java-version file for IDEs
- gradle wrapper 9.3.1 -> 9.7.0, spotless 6.25->8.10.0, spotbugs 4.9.3->4.10.3
- Dockerfile: eclipse-temurin 26-jdk/jre-alpine + -Xmx512m G1GC StringDedup
- docker-compose: bot mem_limit 1g
- CI workflows: setup-java 26
- deps: jda 6.5.0, lavaplayer 2.2.7, logback 1.6.3, slf4j 2.0.18 (stable),
  caffeine 3.2.4, sqlite 3.53.2.1, hikaricp 7.1.0, okhttp 5.5.0,
  junit 5.13.4 + launcher 1.13.4, mockito 5.23.0, bytebuddy 1.18.12,
  checkstyle 13.10.0 (toolVersion), spotbugs plugin 6.4.8, jsoup 1.22.2
- 458 tests green, build green without JAVA_HOME export

gradle/libs.versions.toml

@@ -1,23 +1,24 @@
 [versions]
-jda = "6.4.2"
-lavaplayer = "2.2.6"
+jda = "6.5.0"
+lavaplayer = "2.2.7"
 lavalinkClient = "3.4.0"
 dotenv = "3.2.0"
-slf4j = "2.1.0-alpha1"
-logback = "1.5.18"
+slf4j = "2.0.18"
+logback = "1.6.3"
 gson = "2.14.0"
-caffeine = "3.2.0"
+caffeine = "3.2.4"
 guice = "7.0.0"
-sqlite = "3.49.1.0"
-hikaricp = "6.3.0"
-okhttp = "5.4.0"
-junit = "5.12.1"
-mockito = "5.15.2"
-junitPlatformLauncher = "1.12.1"
-checkstyle = "10.23.0"
-spotbugs = "4.9.3"
-spotbugsPlugin = "6.1.7"
-jsoup = "1.19.1"
+sqlite = "3.53.2.1"
+hikaricp = "7.1.0"
+okhttp = "5.5.0"
+junit = "5.13.4"
+mockito = "5.23.0"
+bytebuddy = "1.18.12"
+junitPlatformLauncher = "1.13.4"
+checkstyle = "13.10.0"
+spotbugs = "4.10.3"
+spotbugsPlugin = "6.4.8"
+jsoup = "1.22.2"
 
 [libraries]
 jda = { module = "net.dv8tion:JDA", version.ref = "jda" }
@@ -36,6 +37,7 @@ logging-interceptor = { module = "com.squareup.okhttp3:logging-interceptor", ver
 junit-jupiter = { module = "org.junit.jupiter:junit-jupiter", version.ref = "junit" }
 mockito-core = { module = "org.mockito:mockito-core", version.ref = "mockito" }
 mockito-junit-jupiter = { module = "org.mockito:mockito-junit-jupiter", version.ref = "mockito" }
+byte-buddy = { module = "net.bytebuddy:byte-buddy", version.ref = "bytebuddy" }
 junit-platform-launcher = { module = "org.junit.platform:junit-platform-launcher", version.ref = "junitPlatformLauncher" }
 checkstyle = { module = "com.puppycrawl.tools:checkstyle", version.ref = "checkstyle" }
 spotbugs = { module = "com.github.spotbugs:spotbugs", version.ref = "spotbugs" }

gradle/wrapper/gradle-wrapper.properties

@@ -1,7 +1,9 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.3.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.7.0-bin.zip
 networkTimeout=10000
+retries=0
+retryBackOffMs=500
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists