Make both distributions fit to publish

The release workflow was already right; what it would have uploaded was not.
`fluksio` had no readme, so its PyPI page would have been blank — the app
repo's own README is a contributor's map of `frontend/` and `docker/`, which
is the wrong front page for `pip install fluksio`. It now has one of its own,
aimed at somebody who landed on the project page. Both distributions gain
authors, urls, keywords and classifiers; `twine check` passes clean on all
four artifacts where it warned on two before.

The workflow publishes `fluksio-worker` first, because `fluksio` depends on it
and the other order leaves a few seconds — the whole of a first release — in
which the dependency cannot be resolved. `--check-url` makes a re-run skip
what is already uploaded rather than failing on it, which matters because a
version on PyPI can never be replaced.

Licence metadata is deliberately still absent: LICENSE is MIT in somebody
else's name, inherited from the template this was scaffolded from, and whose
it should be is not a decision to make in a commit. NOTEPAD carries it.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012ue1tkFWB1bcGy3aWhCKpU

backend/pyproject.toml

@@ -2,7 +2,25 @@
 name = "fluksio"
 version = "0.1.0"
 description = "Node-based automation engine: flows, dashboards, batch runs"
+readme = "README.md"
 requires-python = ">=3.10"
+authors = [{ name = "Fluksio", email = "stroblme@posteo.de" }]
+keywords = ["automation", "workflow", "dataflow", "experiment-tracking", "mlops"]
+classifiers = [
+    "Development Status :: 3 - Alpha",
+    "Intended Audience :: Developers",
+    "Intended Audience :: Science/Research",
+    "Operating System :: MacOS",
+    "Operating System :: POSIX :: Linux",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
+    "Topic :: Home Automation",
+    "Topic :: Scientific/Engineering",
+    "Topic :: System :: Distributed Computing",
+]
 dependencies = [
     "fastapi[standard]<1.0.0,>=0.114.2",
     "python-multipart<1.0.0,>=0.0.7",
@@ -32,6 +50,11 @@ dependencies = [
     "uv>=0.5",
 ]
 
+[project.urls]
+Homepage = "https://fluksio.com"
+Documentation = "https://docs.fluksio.com"
+"Getting started" = "https://docs.fluksio.com/getting-started/data-science/"
+
 [project.scripts]
 fluksio = "fluksio.cli:main"