Install palace-manager editable in the container

The Poetry to uv migration in #3221 switched the container install from
editable (Poetry's default) to non-editable (uv sync --no-editable).
That change broke palace.manager.scripts.startup's discovery of the
startup_tasks/ directory — the script resolves STARTUP_TASKS_DIR via
Path(__file__).parents[4], which assumes startup.py is at
${root}/src/palace/manager/scripts/startup.py (editable install).
Under --no-editable, startup.py lives inside site-packages and
parents[4] resolves to env/lib/python3.12/ instead of the project root,
so startup_tasks/ is never found.

Drop --no-editable to restore the working layout.

Author: jonathangreen

docker/Dockerfile

@@ -27,10 +27,8 @@ RUN uv sync --frozen --no-dev --no-install-workspace
 
 COPY --chown=palace:palace . /var/www/circulation
 
-# Install the project itself as a non-editable install. Omitting
-# --no-install-project (and passing --no-editable) is the recommended
-# pattern for production Docker builds with uv.
-RUN uv sync --frozen --no-dev --no-editable
+# Install the project itself as an editable install.
+RUN uv sync --frozen --no-dev
 
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 ## Circ-exec Image