Move build system from setuptools to uv, wire uv into CI/CD

Convert both pyproject.toml files to the uv_build backend and turn the
repo into a proper uv workspace (plotstyle moved to src layout, since
uv_build requires the module in its own subdirectory). Dev tooling
moves from an optional-dependencies extra to a dependency-group, and
plotstyle's matplotlib dependency is now its own rather than a
gallery "plotting" extra.

Gitea Actions workflows and the Dockerfile now use astral-sh/setup-uv,
uv sync, uv run, uv build, and uv publish throughout instead of pip,
build, and twine. Also fixes .dockerignore, which was excluding
uv.lock, deploy/, and README.md and would have broken even the
previous Dockerfile's COPY of deploy/entrypoint.sh.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -10,52 +10,48 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: astral-sh/setup-uv@v9.0.0
         with:
           python-version: "3.11"
-          cache: pip
-          cache-dependency-path: pyproject.toml
-      - run: pip install -e ".[dev,plotting]"
-      - run: ruff check gallery plotstyle tests
+          enable-cache: true
+      - run: uv sync --all-packages
+      - run: uv run ruff check gallery plotstyle tests
 
   format:
     name: format:ruff
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: astral-sh/setup-uv@v9.0.0
         with:
           python-version: "3.11"
-          cache: pip
-          cache-dependency-path: pyproject.toml
-      - run: pip install -e ".[dev,plotting]"
-      - run: ruff format --check gallery plotstyle tests
+          enable-cache: true
+      - run: uv sync --all-packages
+      - run: uv run ruff format --check gallery plotstyle tests
 
   typecheck:
     name: typecheck:ty
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: astral-sh/setup-uv@v9.0.0
         with:
           python-version: "3.11"
-          cache: pip
-          cache-dependency-path: pyproject.toml
-      - run: pip install -e ".[dev,plotting]"
-      - run: ty check gallery plotstyle
+          enable-cache: true
+      - run: uv sync --all-packages
+      - run: uv run ty check gallery plotstyle
 
   vulnerabilities:
     name: vulnerabilities:pip-audit
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: astral-sh/setup-uv@v9.0.0
         with:
           python-version: "3.11"
-          cache: pip
-          cache-dependency-path: pyproject.toml
-      - run: pip install -e ".[dev,plotting]"
-      - run: pip-audit --skip-editable
+          enable-cache: true
+      - run: uv sync --all-packages
+      - run: uv run pip-audit --skip-editable
 
   test:
     name: test:pytest
@@ -63,10 +59,9 @@ jobs:
     needs: [lint, format, typecheck, vulnerabilities]
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: astral-sh/setup-uv@v9.0.0
         with:
           python-version: "3.11"
-          cache: pip
-          cache-dependency-path: pyproject.toml
-      - run: pip install -e ".[dev,plotting]"
-      - run: python -m pytest tests/ -v
+          enable-cache: true
+      - run: uv sync --all-packages
+      - run: uv run pytest tests/ -v