fix: replace mutable default arguments with None sentinels across backend

[harshadkhetpal]

Summary

Replaces the nine mutable default arguments in backend/ (ruff B006) with the standard None sentinel + normalization pattern. Python evaluates defaults once at import time, so = {} / = [] defaults are shared across every call — a latent cross-request state-leak hazard in long-lived Django workers:

• api_v2/deployment_helper.py — tag_names: list[str] = []
• workflow_manager/endpoint_v2/queue_utils.py — connector_settings: dict = {} ×2
• workflow_manager/endpoint_v2/source.py — file_hashes: dict[str, FileHash] = {}
• workflow_manager/workflow_v2/dto.py — keys_to_remove: list[str] = []
• workflow_manager/workflow_v2/views.py — hash_values_of_files: dict[str, FileHash] = {}
• workflow_manager/workflow_v2/workflow_helper.py — same parameter ×3 (run_workflow, pipeline execution, execution-action dispatch)

Each signature becomes ... | None = None with a param = param or {} (or []) normalization as the first statement after the docstring, so all existing callers — including those passing None explicitly — get identical behavior.

Testing

python -m py_compile passes on all seven files; ruff check --select B006 on the touched paths goes from 9 errors to clean.

🤖 Generated with Claude Code

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[greptile-apps]

Greptile Summary

Replaces shared mutable collection defaults with per-call None sentinels across backend workflow and deployment helpers.

• Normalizes optional file-hash mappings throughout workflow orchestration and source enumeration.
• Normalizes optional queue connector settings, deployment tags, and metadata-removal keys.
• Preserves existing behavior for omitted and explicitly None arguments.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

Important Files Changed

Filename	Overview
backend/api_v2/deployment_helper.py	Replaces the shared tag-name list default with an optional sentinel and per-call list.
backend/workflow_manager/endpoint_v2/queue_utils.py	Replaces shared connector-settings defaults in both queue factory methods.
backend/workflow_manager/endpoint_v2/source.py	Replaces the shared file-hash default used during source enumeration.
backend/workflow_manager/workflow_v2/dto.py	Replaces the shared metadata-key removal list with a per-call list.
backend/workflow_manager/workflow_v2/views.py	Normalizes the optional file-hash mapping at the workflow view boundary.
backend/workflow_manager/workflow_v2/workflow_helper.py	Applies optional file-hash sentinels consistently across workflow execution entry points.

_{Reviews (2): Last reviewed commit: "[pre-commit.ci] auto fixes from pre-comm..." | Re-trigger Greptile}

[sonarqubecloud]

Quality Gate passed

Issues
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud