Default stageOutMode to 'copy' for Google Batch executor

[rhassaine]

Summary

• Default stageOutMode to copy for Google Batch tasks when not explicitly set by the user
• Fixes task failures during output unstaging when running on Google Batch with scratch enabled

Problem

On Google Batch, task outputs are unstaged from local scratch (local SSD) to a gcsfuse-mounted work directory, which is always a cross-device operation. The default move mode uses mv which fails in two scenarios:

1. Overlapping output declarations: When a process declares both a directory and files inside it (e.g. path("outdir/") and path("outdir/*.txt")), mv moves the directory first (with all contents), causing subsequent file moves to fail with No such file or directory

2. Symlinked inputs: When staged input files are symlinks pointing back to the work directory, mv detects source and target as the same file and fails with 'X' and 'Y' are the same file

Fix

After super(bean) in GoogleBatchScriptLauncher, default stageoutMode to copy on the SimpleFileCopyStrategy if the user hasn't explicitly set a stageOutMode. This uses cp -fRL instead of mv -f for unstaging, which handles both failure scenarios.

Test plan

• Tested with a minimal pipeline on Google Batch with overlapping output declarations (path("outdir/") + path("outdir/*.txt")) — both tasks succeeded
• Verified that explicitly setting stageOutMode in config still takes precedence (the fix only applies when bean.stageOutMode is not set)

🤖 Generated with Claude Code

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