[PierreRaybaut]

Summary

Fixes #70: custom colormaps are now stored in the configuration directory of the application, instead of a ~/.none directory shared by all applications.

Root cause

• plotpy.config.CONF had no application name, so CONF.get_path() resolved to ~/.none (and created it).
• CUSTOM_COLORMAPS_PATH was computed once at import time: an application naming PlotPy's configuration afterwards never got its own custom colormaps.

As a result, the location depended on the import order. For example, the DataLab application used ~/.plotpy, whereas DataLab scripts and tests used ~/.none, and DataLab's intended ~/.DataLab_v1/plotpy was never used.

Changes

• CONF is now a PlotPyUserConfig, named "plotpy" by default:
  • set_application() calls registered callbacks;
  • get_path() no longer creates the configuration directory, which is only created when a file is written.
• plotpy.mathutils.colormap:
  • new get_custom_colormaps_path(), computed on demand (CUSTOM_COLORMAPS_PATH remains available through a module __getattr__);
  • new reload_custom_colormaps(), called on each CONF.set_application(), which updates CUSTOM_COLORMAPS and ALL_COLORMAPS in place (they are imported by name elsewhere);
  • migration: if the application's custom colormaps file does not exist yet, colormaps from the legacy .none and .plotpy directories are merged and copied into it. Legacy files are left untouched.
• Tests: new test_colormap_config.py, plus an isolated_config_dir fixture so that colormap tests (including test_colormap_manager) no longer write into the user's real configuration directory.
• Release notes (2.12.0, bug fixes).

Resulting locations

Context	Before	After
PlotPy alone	~/.none	~/.plotpy
Application calling CONF.set_application("MyApp/plotpy", ...) after import	~/.none or ~/.plotpy	~/.MyApp/plotpy
DataLab (application, scripts, tests)	~/.plotpy or ~/.none	~/.DataLab_v1/plotpy

(~ is ~/.config on Linux.)

Known limitation

Migration happens once per application, when its file does not exist yet. A user whose ~/.plotpy file was already written (e.g., by DataLab 1.3) keeps only that file for standalone PlotPy applications: colormaps saved only in ~/.none are not merged into it.

Tests

• New tests fail without the fix and pass with it.
• Full suite: 428 passed, 16 skipped (Windows, PyQt5, Python 3.14).
• Checked with DataLab develop in an isolated home containing legacy .none and .plotpy files: both the application and the script entry points now load the merged colormaps from ~/.DataLab_v1/plotpy.