build: let uv track git version changes; copy full checkout in Docker

Add uv cache-keys for the commit and tags so the editable install is
refreshed when the git state changes, and copy the complete checkout
(with .git) into the builder so setuptools-scm sees a clean worktree.
Previously the partial copy made git describe report a dirty tree and
tagged Docker builds got a development version suffix.

Dockerfile

@@ -20,11 +20,10 @@ COPY pyproject.toml uv.lock .python-version ./
 RUN --mount=type=cache,target=/root/.cache/uv \
     uv sync --frozen --no-dev --no-install-project
 
-# Then install the project itself as a regular wheel. The git metadata is
-# required by setuptools-scm to derive the package version.
-COPY README.md ./
-COPY src ./src
-COPY .git ./.git
+# Then install the project itself. The full checkout (including .git) is
+# copied so setuptools-scm sees a clean worktree and derives the version
+# from the closest release tag.
+COPY . .
 RUN --mount=type=cache,target=/root/.cache/uv \
     uv sync --frozen --no-dev --no-editable