Validate Jobflow workflow outputs

[Andrew-S-Rosen]

Summary

• Make every tests/jobflow execution inspect a concrete returned result.
• Resolve upstream quacc jobs automatically inside Jobflow job arguments and ordinary containers.
• Remove explicit .output composition from quacc-decorated Jobflow workflows.
• Preserve native Jobflow syntax in tests that intentionally demonstrate @jf.job.
• Use the plain file-transfer specification API introduced by Replace Copy with plain file-transfer specs #3409 for deferred copy_files directory references.
• Remove the obsolete Jobflow-specific JobflowCopy compatibility wrapper after merging current main.

Why

ensure_success=True only confirms that Jobflow did not mark execution as failed. It does not prove that the expected value was returned or that downstream jobs received usable outputs. Quacc workflows also need to remain workflow-engine agnostic rather than requiring Jobflow-specific .output access.

PR #3409 replaced custom copy wrappers with ordinary list-of-dictionary transfer specifications. Keeping the old Jobflow wrapper after merging that PR caused an import from the deleted job_argument.py module, so this branch now relies entirely on Jobflow's normal argument traversal.

Validation

• Jobflow test suite: 27 passed
• Ruff lint and formatting checks
• Final audit: all jf.run_locally calls in tests/jobflow capture and inspect responses
• Final audit: no explicit .output calls in src/quacc/recipes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (a41366b) to head (6eb1d87).
⚠️ Report is 25 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main     #3405   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          102       102           
  Lines         4356      4369   +13     
=========================================
+ Hits          4356      4369   +13     

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