Summary

• Use a stable package/resource prefix in ComponentClassLoaderTest instead of the machine-specific temporary directory path.
• Create the test resource explicitly under the JUnit temp directory.
• Avoid failures when java.io.tmpdir contains dotted path segments such as 1.0-SNAPSHOT.

Root Cause

ComponentClassLoader converts package prefixes to resource path prefixes by replacing . with /. The test previously used the absolute @TempDir path as the prefix, so dotted path segments were rewritten and no longer matched the resource name.

Fixes #3437.

Test Plan

• mvn -pl fluss-common -Dtest=ComponentClassLoaderTest test
• mvn -pl fluss-common test

AI-assisted changes - reviewed by human developer