Migrate from Poetry to uv package manager

[Copilot]

This PR migrates the project from Poetry to uv, a modern, fast Python package manager and resolver written in Rust.

Changes

Build System

• Replaced Poetry build backend with Hatchling in pyproject.toml
• Converted Poetry dependency groups to standard Python [project.optional-dependencies]
• Added proper package configuration for the single-file squiral.py module
• Replaced poetry.lock with uv.lock for dependency locking

Dependency Management

• Updated requirements-tool.in to use uv instead of poetry
• Regenerated requirements-tool.txt with uv's dependency tree (removed all Poetry-related packages)
• Updated upgrade script (scripts/upgrader.sh) to use uv lock --upgrade

CI/CD

• Updated .github/workflows/codecov.yml to use uv:
  • Added astral-sh/setup-uv@v5 action for setup
  • Changed dependency installation to uv sync --all-extras
  • Updated test execution to uv run pytest
  • Enabled uv.lock caching for faster CI runs

Benefits

• Faster: uv is 10-100x faster than traditional tools like pip and Poetry
• Modern: Uses the latest Python packaging standards (PEP 621, PEP 517)
• Simpler: Reduced configuration complexity and fewer dependencies
• Compatible: Works seamlessly with existing pip-based workflows

Verification

All 109 tests pass with 100% code coverage maintained. The migration is fully backwards compatible for end users.

New development commands:

# Install dependencies
uv sync --all-extras

# Run tests
uv run pytest --cov=. --cov-report=term-missing

# Run the script
uv run python squiral.py 7

# Upgrade dependencies
uv lock --upgrade

Closes #[issue_number]

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Use uv instead of poetry</issue_title>
<issue_description>In this repo, poetry has been used. From now on, uv should be used in this project.</issue_description>

<agent_instructions>Act like a principal software engineer. You are very good at python and software architecture. Discover all the repo components. Generate poetry->uv transformation codes. Fix unit tests and CI/CD pipelines if needed.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

Fixes #44

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (fd0c373) to head (55ea216).
⚠️ Report is 60 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##            master       #45   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            3         3           
  Lines           59        59           
=========================================
  Hits            59        59           

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