bump version to 0.24, add changelog entry and publish-process docs

doc/devel.rst

@@ -184,3 +184,57 @@ Stability of the DAC has been tested by measuring the shifts of resonance freque
 
 The offset of the PFG amplifier was adjusted via the offset potentiometer on the DAC board. There is also an offset adjustment possible at the PFG amplifier directly. For adjustment, the signal of water in a sample tube with a 0.5 mm teflon stripe perpendicular to the magnetic field B0 was recorded. First, the PFG power supply has been switched off and the sample was shimmed with the room temperature shims until the longest decay time T*2 of the FID has been achieved. After this, the PFG was switched on and the offset has been adjusted to cause least distortion in the spectrum.
 
+*******************
+Publish new version
+*******************
+
+.. warning::
+
+   ``__version__`` in ``src/damaris/__init__.py`` and the top entry of
+   ``debian/changelog`` must carry the same version number at every
+   release. If they drift apart, the Debian package version no longer
+   matches the application version.
+
+1. Commit all code changes intended for the release.
+
+2. Bump ``__version__`` in ``src/damaris/__init__.py``. This constant
+   is the single source of truth for the application version and
+   follows the simple ``X.Y`` scheme used so far (a minor release
+   increments the second number, e.g. 0.22 -> 0.23).
+
+3. Add a new entry at the top of ``debian/changelog`` with the same
+   version number and a bullet list of the user visible changes. The
+   Debian package version does not follow ``__version__``
+   automatically; it is defined solely by this file. Either edit
+   ``debian/changelog`` directly or run ``dch`` (from the
+   ``devscripts`` package), which prepends the entry for you. Match
+   the entry format already used in this file:
+
+   .. code-block:: text
+
+      python3-damaris (X.Y) stable; urgency=medium
+
+        * bullet list of user visible changes
+
+       -- Full Name <email>  Day, DD Mon YYYY HH:MM:SS +0200
+
+   The maintainer line at the end is indented by two spaces and its
+   date must be in RFC-2822 format, which ``date -R`` produces.
+
+4. Commit the version bump and the changelog entry together in one
+   commit. The repository currently carries no version tags, so no
+   tagging step is defined; confirm with ``git tag -l`` before
+   introducing one.
+
+5. Everything else picks up the new version automatically. The Sphinx
+   documentation reads ``damaris.__version__`` in ``doc/conf.py``, and
+   ``pyproject.toml`` declares the package version dynamically via
+   ``[tool.setuptools.dynamic]`` with ``attr = "damaris.__version__"``,
+   so neither needs a manual edit. On a push to ``main`` the Debian CI
+   pipeline ``.gitea/workflows/debian-build.yml`` builds the package
+   with ``dpkg-buildpackage`` for bookworm and trixie; the version of
+   the resulting ``.deb`` is taken from ``debian/changelog``.
+
+``DEVELOPER.md`` at the repository root keeps a short note about the
+version bump in ``src/damaris/__init__.py``; this section expands it.
+