ci: add a windows runner

[avsm]

this will fail until #110 but checking it gets as far as the build

[avsm]

@copilot look at the windows failure and figure out why the cram binary cannot be found on windows

[Copilot]

Pull request overview

This PR adds Windows support to the CI pipeline by including windows-latest in the test matrix and adapting the workflow to handle platform-specific requirements for GDAL installation and test execution.

• Added Windows runner to the CI matrix alongside existing Ubuntu and macOS runners
• Modified GDAL installation for Windows to use a third-party GitHub Action instead of Chocolatey
• Split test execution into separate Unix and Windows steps to accommodate PowerShell syntax differences

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
pyproject.toml	Added pip to build-system requirements (though this may not be necessary)
.github/workflows/ci.yml	Added Windows runner to matrix, reorganized setup steps, implemented Windows-specific GDAL installation and test execution

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[Copilot]

cram is being installed twice in the Windows workflow: once in this step (line 37) and again in the "Test (Windows)" step (line 56). The installation here is redundant since uv sync --locked --all-extras --dev in the Build step should install all development dependencies including cram. Consider removing the cram installation from this line.

Suggested change

	run: uv pip install pip cram
	run: uv pip install pip

[Copilot]

cram is being installed again here, but it should already be available from the uv sync --locked --all-extras --dev command in the Build step (line 46). This redundant installation should be removed. If cram is not being installed by uv sync, it suggests it's not properly declared in the project's dev dependencies, which should be fixed there instead.

Suggested change

uv pip install cram

[avsm]

@copilot look at the test failures; cram is not being found

[dra27]

The main error is the regexp in _parse_npy_filename, I think - it's matching on forward slashes only (around L486 in geotessera/tiles.py)

[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.

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[Copilot]

Calling tmp.close() explicitly inside the context manager is problematic. The file will be closed twice - once by the explicit close() call and again when exiting the with block. Instead, use the context manager's file handle and close it naturally, or restructure to close and open outside the context manager. Consider using delete=False with the context manager exiting naturally, then calling to_file() after the with block.

Suggested change

	tmp.close()
	country_gdf.to_file(tmp.name, driver="GeoJSON")
	country_geojson_file = tmp.name
	tmp_name = tmp.name
	country_gdf.to_file(tmp_name, driver="GeoJSON")
	country_geojson_file = tmp_name

[Copilot]

The property PSIsContainer is deprecated in PowerShell 7+. Consider using the PSIsDirectory property instead for future compatibility. This should be: Sort-Object { -not $_.PSIsDirectory }, Name