[CHORE]: Raise pylint from 9.16/10 -> 10/10

[crivetimihai]

🔧 Chore Summary

Bring the project's pylint score up to a perfect 10/10 while keeping all tests and smoke-tests green.

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🧱 Area Affected

• Pre-commit hooks / linters
• Build system or Makefile (make pylint, make autoflake, make isort, make black, make pre-commit)
• GitHub Actions / CI

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⚙️ Context / Rationale

A 10/10 score reduces tech debt and blocks regressions. Current failures are mainly no-value-for-parameter, wrong-import-order, and missing docstrings.

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📦 Related Make Targets

Target	Purpose
make autoflake	Remove unused imports / vars
make isort	Sort & group imports
make black	Reformat code (PEP 8)
make pre-commit	Run all configured hooks
make pylint	Pylint static analysis
make lint	Full lint meta-target
make test	Unit / integration tests
make smoketest	Minimal E2E sanity check

All bold targets are mandatory; CI must fail if any one does.

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📋 Acceptance Criteria

• make pylint prints 10.00/10 and exits 0.
• make autoflake, make isort, make black, make pre-commit run clean with no diffs.
• make test and make smoketest pass.
• GitHub Actions enforces the above (e.g. --fail-under=10.0).
• Changelog entry under "Maintenance".

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🛠️ Task List (suggested)

1. Triage pylint output; fix high-impact E**** first.
2. Import order & unused symbols
   • Run make autoflake -> make isort -> make black to auto-fix bulk issues.
3. Address remaining pylint warnings/errors; suppress only with justification.
4. Run hooks locally: make pre-commit.
5. Execute full test suite & smoke tests
6. Test locally with make venv install install-dev test smoketest
7. Test in containers make docker-prod docker-run-ssl-host
8. Test with compose (Postgres + Redis) make compose-up after changing docker-compose.yaml to use :latest local image
9. Test database migrations (alembic)
10. Test with helm chart deployment in minikube - make minikube-install minikube-start and deploy the helm chart under charts/mcp-stack (see README)
11. Test Pypi package builds and works well - make devpi-install devpi-init devpi-start devpi-clean and try mcpgateway
12. Raise CI threshold to --fail-under=10.0.
13. Commit with message chore(lint): achieve pylint 10/10.

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🧩 Additional Notes

• Duplicate-code warnings can be suppressed with a comment if refactor risk is high.
• Keep commits small and self-contained; consider one per subsystem to ease review.

[crivetimihai]

I will work on the following files:

• mcpgateway/cli.py
• mcpgateway/translate.py

[ChrisPC-39]

Hi! I will work on the following:

• mcpgateway.services.gateway_service
• mcpgateway.schemas
• mcpgateway.transports.streamablehttp_transport
• mcpgateway.handlers.sampling

Will take anything available after these are finished.

[crivetimihai]

Fixed and merged:
mcpgateway/cli.py
mcpgateway/translate.py

[ChrisPC-39]

Work In Progress PR #239

Files that still require attention:

• mcpgateway.db
• mcpgateway.handlers.sampling
• mcpgateway.main
• mcpgateway.cache.session_registry
• mcpgateway.translate
• mcpgateway.services.gateway_service

Some of these require some code changes, so updates are slower.
Do NOT use isort after pylint! isort will re-order imports and cause pylint to fail again!