fix: copy Maven artifacts into workspace instead of mounting $HOME/.m2

Issue: Docker volume mount from $HOME/.m2 wasn't working in GitHub Actions
- Container couldn't access the locally built SNAPSHOT JARs
- Maven failed with 'Could not find artifact seaweedfs-hadoop3-client:3.80.1-SNAPSHOT'

Solution: Copy Maven repository into workspace
1. In CI: Copy ~/.m2/repository/com/seaweedfs to test/java/spark/.m2/repository/com/
2. docker-compose.yml: Mount ./.m2 (relative path in workspace)
3. .gitignore: Added .m2/ to ignore copied artifacts

Why this works:
- Workspace directory (.) is successfully mounted as /workspace
- ./.m2 is inside workspace, so it gets mounted too
- Container sees artifacts at /root/.m2/repository/com/seaweedfs/...
- Maven finds the 3.80.1-SNAPSHOT JARs with our debug logging!

Next run should finally show the [DEBUG-2024] logs! 🎯

.github/workflows/spark-integration-tests.yml

@@ -199,14 +199,18 @@ jobs:
         curl -s http://localhost:9333/dir/status | jq '.' || echo "jq not available"
         echo "✓ Volume server registered, volumes will be created on-demand during tests"
 
-    - name: Verify Maven artifacts before tests
+    - name: Prepare Maven repository for Docker
+      working-directory: test/java/spark
       run: |
-        echo "Verifying Maven artifacts are available in ~/.m2/repository..."
-        echo "Checking for SNAPSHOT artifacts:"
-        find ~/.m2/repository/com/seaweedfs -name "*3.80.1-SNAPSHOT*" 2>/dev/null | sort || echo "No SNAPSHOT artifacts found!"
+        echo "Copying Maven artifacts into workspace for Docker access..."
+        mkdir -p .m2/repository/com
+        cp -r ~/.m2/repository/com/seaweedfs .m2/repository/com/
+        
+        echo "Verifying copied artifacts:"
+        find .m2/repository/com/seaweedfs -name "*3.80.1-SNAPSHOT*" | sort
         echo ""
-        echo "All seaweedfs JARs:"
-        find ~/.m2/repository/com/seaweedfs -name "*.jar" 2>/dev/null | sort
+        echo "Directory size:"
+        du -sh .m2/repository/com/seaweedfs
         
     - name: Run Spark integration tests in Docker
       working-directory: test/java/spark

test/java/spark/.gitignore

@@ -1,5 +1,6 @@
 # Maven
 target/
+.m2/
 pom.xml.tag
 pom.xml.releaseBackup
 pom.xml.versionsBackup

test/java/spark/docker-compose.yml

@@ -71,7 +71,7 @@ services:
     container_name: seaweedfs-spark-tests
     volumes:
       - .:/workspace
-      - ${HOME}/.m2:/root/.m2
+      - ./.m2:/root/.m2
     working_dir: /workspace
     environment:
       - SEAWEEDFS_TEST_ENABLED=true