[Daxia] [ FastAPI ] Fix duplicate operation IDs across routers

[daxia778]

/claim #764

Summary

• Generate default FastAPI operation IDs as method + route path/prefix + function name.
• Sanitize generated IDs to lowercase ASCII alphanumeric characters and underscores.
• Generate method-specific OpenAPI IDs for multi-method routes.
• Add numeric suffixes for generated operation ID collisions after sanitization.

Demo

https://github.com/daxia778/Bounty-Hunters/releases/download/issue-764-demo-f3b13904/fastapi-operation-id-764-demo-f3b13904.mp4

Validation

• UV_PYTHON=<Python 3.12> uv run ruff check fastapi/utils.py fastapi/openapi/utils.py tests/test_operation_id_generation.py
• UV_PYTHON=<Python 3.12> uv run ruff format --check fastapi/utils.py fastapi/openapi/utils.py tests/test_operation_id_generation.py
• UV_PYTHON=<Python 3.12> uv run python -m pytest tests/test_generate_unique_id_function.py tests/test_operation_id_generation.py -q
• git diff --check

[github-actions]

Unfortunately the changes in this PR didn't fully resolve the issue. Please rework your solution and submit a new pull request.

Make sure to review the acceptance criteria in the linked issue and verify all conditions are met before resubmitting. See CONTRIBUTING.md for guidelines.