2.7.0.1 jdk8 (#10)

* [release] update scm

* Restore client-only modules for split repository (#9)

The split client repository needs to carry MCP registration, beat registration, Spring Boot starters, and discovery registration without inheriting the main repository JDK upgrade constraints. This restores the client-side module surface on the JDK 8 release base, rebases dependencies onto Spring Boot 2/JDK 8 compatible lines, and expands CI coverage through JDK 25 after local compatibility verification.

Constraint: Client artifacts must remain JDK 8 compatible while validating JDK 17, 21, 23, and 25

Constraint: The split repository does not define the release Maven profile, so CI uses ./mvnw -B clean test

Rejected: Move the client back under the main repository | it would keep client compatibility tied to admin/bootstrap JDK upgrade timing

Rejected: Keep JDK 23 and 25 as local-only checks | CI would not catch future toolchain regressions

Confidence: medium

Scope-risk: broad

Directive: Do not upgrade client runtime dependencies without rerunning the JDK 8 compatibility build

Tested: ./mvnw -DskipTests compile

Tested: ./mvnw test

Tested: JAVA_HOME=/Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home ./mvnw -B clean test

Tested: JAVA_HOME=/Users/aias/Library/Java/JavaVirtualMachines/corretto-17.0.13/Contents/Home ./mvnw -B clean test -Prelease

Tested: JAVA_HOME=/Users/aias/Library/Java/JavaVirtualMachines/openjdk-21.0.2/Contents/Home ./mvnw -B clean test -Prelease

Tested: JAVA_HOME=/Users/aias/Library/Java/JavaVirtualMachines/openjdk-25.0.2/Contents/Home ./mvnw -B clean test

Tested: JAVA_HOME=/tmp/shenyu-jdks/jdk-23.0.2+7/Contents/Home ./mvnw -B clean test

Not-tested: End-to-end registration against matching admin/bootstrap runtime
105 files changed