Implement the frame='none' syntax for no frames

[seisman]

Closes #4403.

Preview: https://pygmt-dev--4404.org.readthedocs.build/en/4404/api/generated/pygmt.Figure.basemap.html#pygmt.Figure.basemap

[github-actions]

Summary of changed images

This is an auto-generated report of images that have changed on the DVC remote

Status	Path
added	pygmt/tests/baseline/test_basemap_frame_none.png

Image diff(s)

Details

Added images

• test_basemap_frame_none.png

Modified images

Path	Old	New

Report last updated at commit f34f44c

[Copilot]

Pull request overview

Adds a Pythonic frame="none" option across PyGMT plotting APIs to request “no frame” behavior by translating it to GMT’s -B+n under the hood.

Changes:

• Map frame="none" to the GMT -B+n syntax in the alias system (common -B handling).
• Expand frame type annotations across affected plotting functions to include Literal["none"].
• Add/extend tests, baseline image, and update docs/examples to demonstrate the new syntax.

Reviewed changes

Copilot reviewed 27 out of 27 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pygmt/alias.py	Implements the frame="none" → +n mapping for common -B handling.
pygmt/helpers/decorators.py	Updates common frame docstring snippet to document frame="none".
pygmt/src/basemap.py	Updates frame type hint to accept "none".
pygmt/src/coast.py	Updates frame type hint to accept "none".
pygmt/src/colorbar.py	Updates frame type hint and documents frame="none" behavior.
pygmt/src/contour.py	Updates frame type hint to accept "none".
pygmt/src/grdcontour.py	Updates frame type hint to accept "none".
pygmt/src/grdimage.py	Updates frame type hint to accept "none".
pygmt/src/grdview.py	Updates frame type hint to accept "none".
pygmt/src/histogram.py	Updates frame type hint to accept "none".
pygmt/src/image.py	Updates frame type hint to accept "none".
pygmt/src/legend.py	Updates frame type hint to accept "none".
pygmt/src/meca.py	Updates frame type hint to accept "none".
pygmt/src/plot.py	Updates frame type hint to accept "none".
pygmt/src/plot3d.py	Updates frame type hint to accept "none".
pygmt/src/rose.py	Updates frame type hint to accept "none".
pygmt/src/solar.py	Updates frame type hint to accept "none".
pygmt/src/subplot.py	Updates frame type hint to accept "none".
pygmt/src/ternary.py	Updates frame type hint to accept "none".
pygmt/src/text.py	Updates frame type hint to accept "none".
pygmt/src/tilemap.py	Updates frame type hint to accept "none".
pygmt/src/velo.py	Updates frame type hint to accept "none".
pygmt/src/wiggle.py	Updates frame type hint to accept "none".
pygmt/tests/test_alias_system.py	Adds coverage asserting frame="none" becomes -B+n via common-parameter aliasing.
pygmt/tests/test_basemap.py	Adds an image-comparison test covering frame="none" in basemap and colorbar.
pygmt/tests/baseline/test_basemap_frame_none.png.dvc	Adds the baseline artifact metadata for the new image test.
examples/gallery/maps/choropleth_map.py	Updates an example to use frame="none" instead of raw "+n".

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[seisman]

@GenericMappingTools/pygmt-maintainers Please give this PR final reviews. Plan to merge it in three days.