build: pin lettuce-core to explicit version to fix Netty 4.1/4.2 conflict

spring-boot-data-redis 4.0.1 pulls spring-boot-netty which upgrades
netty-common to 4.2.x while lettuce-core 6.8.x keeps other Netty
artifacts at 4.1.x, causing AbstractMethodError at startup. Pinning
lettuce-core to the project-defined lettuceVersion (7.2.1) aligns
all Netty modules to 4.2.x as expected by Spring Boot 4.0.

Also rename CLAUDE.md → AGENTS.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: sonus21

AGENTS.md

@@ -0,0 +1,28 @@
+# Project rules for AI tools
+
+## Commits
+
+**Never add `Co-Authored-By:` trailers crediting any AI tool to a git commit.**
+
+This includes any AI assistant (e.g. GitHub Copilot, Cursor, Codeium, Gemini, and similar tools). Commits must list a human author only — AI tools are not co-authors.
+
+**You may add an `Assisted-By:` trailer naming the tool.** Example:
+
+```
+Assisted-By: <tool name>
+```
+
+Use a short, plain tool name. No emails, no URLs, no marketing taglines. One trailer per commit is enough.
+
+If your default commit template includes a `Co-Authored-By:` for an AI tool, strip it before committing and replace it with `Assisted-By: <tool>` instead. This rule applies to all branches and to rewrites.
+
+## Versioning
+
+**Never change the version declared in any project file** (`build.gradle`, `gradle.properties`, `pom.xml`, etc.) that is already stored locally.
+
+If you need to publish a patched or experimental build, append a suffix to the existing version string instead of bumping the base version. Examples:
+
+- `4.0.0-RC6` → `4.0.0-RC6-fix1`
+- `4.0.0-RC6` → `4.0.0-RC6-SNAPSHOT`
+
+Never remove or increment the base version number. The human decides when the official version changes.

CLAUDE.md

@@ -2,6 +2,7 @@ plugins {
     id "org.springframework.boot" version "${springBootVersion}"
     id "war"
 }
+
 dependencies {
     implementation project(":rqueue-spring-boot-starter")
     implementation "org.springframework.boot:spring-boot-starter-data-redis:${springBootVersion}"
@@ -10,7 +11,7 @@ dependencies {
     implementation "ch.qos.logback:logback-core:${logbackVersion}"
     // https://mvnrepository.com/artifact/ch.qos.logback/logback-classic
     implementation "ch.qos.logback:logback-classic:${logbackVersion}"
-    implementation "io.lettuce:lettuce-core"
+    implementation "io.lettuce:lettuce-core:${lettuceVersion}"
     annotationProcessor "org.springframework.boot:spring-boot-configuration-processor:${springBootVersion}"
     providedRuntime "org.springframework.boot:spring-boot-starter-tomcat:${springBootVersion}"
 }